Engine Controls - Self-Diagnostics - Except 2.0L Turbo: Diagnosis Mitsubishi Lancer IX

SYSTEM DIAGNOSIS

Note. Engine management is controlled by an Engine Control Module (ECM) on vehicles with Manual Transaxle (M/T) or by a Powertrain Control Module (PCM) on vehicles with Automatic Transaxle (A/T). ECM/PCM diagnostic memory is retained by direct power supply from battery. Memory is not erased by turning off ignition, but it will be erased if battery or ECM/PCM is disconnected.

ECM/PCM includes On-Board Diagnostics II (OBD-II) software designed to monitor emissions control system over the life of the vehicle. On OBD-II equipped vehicles, the MIL will illuminate only for emissions system related faults. Most of these faults will not cause driveability problems and would go unnoticed by the driver were it not for the MIL. When MIL illuminates, a DTC will be stored. The ECM/PCM may also store DTCs that do not illuminate the MIL. These may be DTCs for faults that no longer exist, provisional codes or for faults that are not emission systems related. DTCs may be retrieved using the manufacturer's MUT-II Scan Tool (MB991502) or a compatible generic scan tool. See ENTERING ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM.

ECM/PCM monitors several different engine control system circuits. If an abnormal input signal occurs, the ECM/PCM will store it in memory as either a provisional code or DTC. A specific DTC indicates a particular system failure, but does not indicate the cause of failure is necessarily within that system. Most faults require that the malfunction be detected during 2 different drive cycles before the MIL is illuminated. On DTCs that use 2 drive cycles, the first occurrence of the fault will store a provisional code. The second occurrence of the fault will set a DTC and illuminate the MIL.

For certain system or component failures, ECM/PCM will enter fail-safe function (limp home mode). In fail-safe mode, ECM/PCM will substitute default values for the faulty component or system.

Each circuit or system monitored by ECM/PCM has particular engine and driving conditions that must be met before ECM/PCM will monitor it. These conditions are the code set criteria. Due to differences in code set criteria, some circuits or systems are monitored almost continuously while others may not be monitored at all during a particular drive cycle. After a repair, it is necessary to run the vehicle under conditions that meet code set criteria in order to verify the repair. This is best done by following the drive cycle related to the DTC. To verify a misfire or fuel trim repair, it is also necessary to operate the vehicle in conditions similar (engine speed, engine load, engine temperature, etc.) to those when the misfire occurred. These conditions are recorded as freeze frame data. Check freeze frame data before erasing DTCs, as freeze frame data will also be erased.

Readiness Test Status

During different parameters of engine operation, the ECM/PCM monitors and runs tests on various inputs, outputs and system functions. There are 6 monitors. One monitor (Other Monitor) passively monitors for shorts, grounds and out of range parameters. It runs continuously. The other 5 monitors actively test different systems and will only run when very specific engine operating conditions have been met. Those monitors may or may not run during any given drive cycle. These 5 monitors have a system readiness test to show whether the particular monitor has been run or not. For additional information on drive cycles, see VERIFYING REPAIRS . A system related Diagnostic Trouble Code (DTC) cannot set until it's monitor has run successfully and readiness test status indicates COMPLETE.

When DTCs are cleared, each readiness test status is set to INCOMPLETE or NOT READY. To complete readiness test status, OBD-II drive cycles related to all on-board diagnostic items should be carried out. See OBD-II DRIVE CYCLES . If vehicle is normal, readiness test status will complete by carrying out OBD-II drive cycle once. MUT-II scan tool will then read COMPLETE. Generic scan tool will read READY. If ECM/PCM detects a malfunction, OBD-II drive cycle must be carried out again before readiness test status will complete. Once readiness test status is complete, ECM/PCM can be checked for DTCs.

VISUAL INSPECTION

Most driveability problems in the engine control system result from faulty wiring, poor electrical connections or leaking air and vacuum hose connections. To avoid unnecessary component testing, perform a visual inspection before beginning self-diagnostic tests.

ENTERING ON-BOARD DIAGNOSTICS

Note. DO NOT skip any steps in self-diagnostic tests or incorrect diagnosis may result. Ensure self-diagnostic test applies to vehicle being tested.

Using Scan Tool

1. Refer to scan tool manufacturer's operation manual for instructions. Before entering on-board diagnostics, see «SERVICE PRECAUTIONS»(ref-152075-S29483572062003011300000) . Locate Data Link Connector (DLC) under instrument panel, near steering column.
2. Turn ignition switch to LOCK position. Connect scan tool to DLC. Turn ignition on. Read and record scan tool self-diagnostic output. Proceed to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-152075-S09950415582003011300000) . If scan tool will not communicate with ECM/PCM, diagnose communication concern. See «SCAN TOOL WILL NOT COMMUNICATE»(ref-152075-S13249849662003011300000) . Turn ignition switch to LOCK position before disconnecting scan tool.

Intermittent Diagnostic Trouble Codes

If DTC was set and DTC diagnostic procedure does not locate fault, problem is intermittent. Most intermittent malfunctions occur from vibration, temperature change, moisture change and poor connections. Try to determine under what specific conditions problem occurs. Try to duplicate those conditions while monitoring circuit suspected of being faulty with data recorder function of scan tool. The following additional checks may assist in identifying a possible intermittent problem

1. Check all pertinent Technical Service Bulletins (TSBs).
2. Visually inspect related wiring connectors for broken, bent, pushed out or corroded terminals.
3. Visually inspect related wiring for chafed, pierced or partially broken wires.
4. Wiggle suspected wire(s) or vibrate suspected component.
5. Apply heat and/or humidity to suspected component.

Provisional DTC

Provisional DTCs are set only during a single drive cycle. ECM (M/T) or PCM (A/T) will detect some malfunctions and set DTCs in memory but may not turn on the Malfunction Indicator Light (MIL). Provisional DTCs do not necessarily indicate a failure of a component or system. If a component or system fails for 2 drive cycles, a hard fault will be stored. See HARD FAILURES under ON-BOARD DIAGNOSTICS in SELF-DIAGNOSTIC SYSTEM. For additional information on provisional DTCs, see VERIFYING REPAIRS .

CLEARING DIAGNOSTIC TROUBLE CODES

Note. Obtain radio anti-theft code before disconnecting battery. When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle.

To clear DTCs using a scan tool, refer to scan tool owner's manual. Ensure DTCs do not reset. Start and warm up engine. Operate vehicle through appropriate drive cycle(s). See VERIFYING REPAIRS . Check for DTCs to confirm repair.

Note. A drive cycle is when engine goes from start to stop and component is monitored in-between. The component's code set criteria must be met while the engine is operating before it will be monitored. Due to this, component may not be monitored every engine start-to-stop cycle.

If DTC was set and DTC diagnostic procedure does not locate fault, problem is intermittent. Most intermittent malfunctions occur from vibration, temperature change, moisture change and poor connections. Try to determine under what specific conditions problem occurs. Try to duplicate those conditions while monitoring circuit suspected of being faulty with data recorder function of scan tool. The following additional checks may assist in identifying a possible intermittent problem

1. Check all pertinent Technical Service Bulletins (TSBs).
2. Visually inspect related wiring connectors for broken, bent, pushed out or corroded terminals.
3. Visually inspect related wiring for chafed, pierced or partially broken wires.
4. Wiggle suspected wire(s) or vibrate suspected component.
5. Apply heat and/or humidity to suspected component.

Scheme 1

Scheme 2

DIAGNOSTIC TROUBLE CODE DEFINITIONS

Note. DTCs can only be retrieved by using a scan tool. See ENTERING ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM.

When Diagnostic Trouble Code (DTC) is obtained, refer to appropriate DTC test procedure under DIAGNOSTIC TESTS .

DIAGNOSTIC TROUBLE CODE INDEX

Scheme 3

DTC Set Conditions

If throttle position sensor output voltage is 1.5 volts or more and engine speed more than 2000 RPM, DTC will set if VAF sensor output frequency has continued to be 60 Hz or less for 2 seconds.

If throttle position sensor output voltage is 2 volts or less and engine speed is less than 2000 RPM, DTC will set if VAF sensor output frequency has continued to be 800 Hz or more for 2 seconds.

Diagnostic Procedure

1. Start and warm engine to normal operating temperature. Using scan tool, check data list item No. 12: VOLUME AIRFLOW SENSOR. Scan tool should read 10 Hz or more at idle. When engine is raced, frequency should increase in relation to increase in engine speed. If scan tool reads as specified, problem is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) . If scan tool does not read as specified, go to next step.
2. Turn ignition on, with engine off. Using a DVOM connected to ground, backprobe and VAF sensor harness connector terminal No. 7. VAF sensor is located on air intake pipe, near air cleaner. If voltage reading is 6-9 volts, go to step 5 . If voltage reading is not 6-9 volts, go to next step.
3. Turn ignition off. Disconnect VAF sensor harness connector and ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T). ECM or PCM is located under right side of dash, near glove compartment. Check for connector or terminal damage. Repair or replace as necessary. After repairs, go to step 9 . If connector and terminals are okay, go to next step.
4. Check for short to ground in circuit between VAF sensor harness connector terminal No. 7 and ECM harness connector C-121 terminal No. 19 (M/T) or PCM harness connector C-120 terminal No. 19 (A/T). Repair as necessary. After repairs, go to step 9 . If circuit is okay, replace VAF sensor.
5. Reconnect all disconnected harness connectors. Start and operate engine at idle. Using DVOM connected to ground, backprobe VAF sensor harness connector terminal No. 7. Voltage reading should be one volt or less with engine idling or 6-9 volts with engine speed at 3000 RPM. If voltage reading is as specified, go to step 8 . If voltage reading is not as specified, go to next step.
6. Turn ignition off. Check for damage in VAF sensor and ECM or PCM harness connectors. Repair or replace as necessary. If harness connectors are okay, go to next step.
7. Check for open in circuit between VAF sensor harness connector and ECM or PCM harness connector. Repair as necessary. After repairs, go to step 9 . If circuit is okay, replace ECM or PCM. After replacing ECM or PCM, go to step 9 .
8. Replace VAF sensor. After replacing sensor, go to next step.
9. Using scan tool, clear DTCs. Test drive vehicle following OBD-II drive cycle other monitor pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under OBD-II DRIVE CYCLES under VERIFYING REPAIRS. Check for DTCs. If DTC P0101 is output, retry diagnostic procedure. If DTC P0101 is not output, inspection is complete.

When engine speed is more than 500 RPM and VAF sensor output frequency has continued to be 3.3 Hz or less for 2 seconds.

1. Start and warm engine to normal operating temperature. Using scan tool, check data list item No. 12: VOLUME AIRFLOW SENSOR. Scan tool should read 10 Hz or more at idle. When engine is raced, frequency should increase in relation to increase in engine speed. If scan tool reads as specified, problem is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) . If scan tool does not read as specified, go to next step.
2. Turn ignition on, with engine off. Using a DVOM connected to ground, backprobe VAF sensor harness connector terminal No. 4. VAF sensor is located on air intake pipe, near air cleaner. If battery voltage is present, go to step 5 . If battery voltage is not present, go to next step.
3. Turn ignition off. Disconnect VAF sensor harness connector. Turn ignition on. Check voltage between ground and VAF sensor harness connector terminal No. 4. If battery voltage is present, go to next step. If battery voltage is not present, repair open or shorted Red/Yellow wire circuit between VAF sensor and MFI relay.
4. Turn ignition off. Check VAF sensor harness connector for damage. Repair or replace as necessary. After repairs, go to step 13 . If harness connector is okay, check for faulty circuit between VAF sensor and MFI relay. Repair as necessary. After repairs, go to step 13 .
5. Check VAF sensor harness connector for damage. Repair or replace as necessary. After repairs, go to step 13 . If harness connector is okay, go to next step.
6. Turn ignition on. Check voltage between ground and VAF sensor harness connector terminal No. 3. If voltage reading is 4.8-5.2 volts, go to step 9 . If voltage reading is not 4.8-5.2 volts, go to next step.
7. Turn ignition off. Check ECM or PCM harness connectors. ECM or PCM is located behind right side of dash, near glove compartment. Repair or replace as necessary. After repairs, go to step 13 . If harness connectors are okay, go to next step.
8. Check for short to ground in circuit between VAF sensor harness connector terminal No. 3 and ECM harness connector C-115 terminal No. 90 (M/T) or PCM harness connector C-118 terminal No. 65 (A/T). Repair as necessary. After repairs, go to step 13 . If circuit is okay, replace ECM or PCM. After replacing ECM or PCM, go to step 13 .
9. Check continuity between ground and VAF sensor harness connector terminal No. 5. If continuity exists, go to step 12 . If continuity does not exist, go to next step.
10. Check ECM or PCM harness connectors for damage. Repair or replace as necessary. After repairs, go to step 13 . If harness connectors are okay, go to next step.
11. Check for open in circuit or harness damage between VAF sensor terminal No. 5 and ECM harness connector C-119 terminal No. 40 (M/T) or PCM harness connector C-120 terminal No. 16 (A/T). Repair as necessary. After repairs, go to step 13 . If no problem is found, replace ECM or PCM. After replacing ECM or PCM, go to step 13 .
12. Check VAF sensor and ECM or PCM harness connectors for damage. Repair or replace as necessary. After repairs, go to next step. If harness connectors are okay, replace VAF sensor.
13. Test drive vehicle following OBD-II drive cycle other monitor pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under OBD-II DRIVE CYCLES under VERIFYING REPAIRS. Check for DTCs. If DTC P0102 is output, retry diagnostic procedure. If DTC P0102 is not output, inspection is complete.

Scheme 4

Note. Barometric Pressure (BARO) sensor is part of the Volume Airflow (VAF) sensor and cannot be serviced separately.

Check conditions are when barometric pressure is less than 11 psi (76 kPa). Judgement criteria is when during 15 times of driving, the changes in the sensor output voltage should be 0.015 volt, equivalent to 0.06 psi (0.4 kPa) or less. Make sure that engine coolant temperature is 162°F (72° C) or greater during each of the 15 times of driving. Also, during each of the 15 times of driving, make sure that after engine has been started, the engine coolant temperature has increased to 41°F (23°C) or greater.

1. Turn ignition on, with engine off. Using scan tool, check for DTCs. If DTC P0107 is set, diagnose DTC first. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-152075-S09950415582003011300000) . If DTC P0107 is not set, go to next step.
2. Turn ignition off. Check BARO sensor harness connector for damage. BARO sensor is integral with airflow sensor and located in air intake hose. Repair or replace as necessary. After repairs, go to step 9 .
3. Disconnect BARO sensor harness connector. Using a DVOM, check resistance between ground and BARO sensor harness connector terminal No. 5. Resistance should be less than 2 ohms. If continuity is as specified, go to step 6 . If continuity is not as specified, go to next step.
4. Check ECM or PCM harness connectors. ECM or PCM is located behind glove compartment. Repair or replace as necessary. After repairs, go to step 9 . If connectors are okay, go to next step.
5. Check BARO sensor circuit for open or harness damage. Check ECM harness connector C-119 (M/T) or PCM harness connector C-120 (A/T) for damage. Repair as necessary. After repairs, go to step 9 . If circuits or connectors are okay, replace ECM or PCM. After replacing ECM or PCM, go to step 9 .
6. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 9 . If connector is okay, go to next step.
7. Check for open in BARO sensor circuit between BARO sensor harness connector and ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T). Repair as necessary. After repairs, go to step 9 . If circuit or connector is okay, go to next step.
8. Replace BARO sensor. Test drive vehicle following OBD-II drive cycle other monitor pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under OBD-II DRIVE CYCLES under VERIFYING REPAIRS. Check for DTCs. If DTC P0106 is output, replace ECM or PCM. If DTC P0103 is not output, go to next step.
9. Test drive vehicle following OBD-II drive cycle other monitor pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under OBD-II DRIVE CYCLES under VERIFYING REPAIRS. Check for DTCs. If DTC P0106 is output, retry diagnostic procedure. If DTC P0106 is not output, inspection is complete.

Check conditions are when 2 seconds or more have passed since the starting sequence was completed and battery voltage is more than 8 volts. DTC is set when BARO sensor output has continued to be 7.1 psi (49 kPa) or less (about 15,000 ft. above sea level) for 10 seconds.

1. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the data reading mode for data list item 25: BAROMETRIC PRESSURE SENSOR. See «BAROMETRIC PRESSURE SENSOR SPECIFICATIONS»(ref-152075-S24317171992003011300000) table. Turn ignition switch to LOCK position. If sensor is not operating properly, go to next step. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) . BAROMETRIC PRESSURE SENSOR SPECIFICATIONS Altitude - Feet (Meters) Pressure 0 (0) 101 kPa 1969 (600) 95 kPa 3937 (1200) 88 kPa 5906 (1800) 81 kPa
2. Check the sensor output voltage at BARO sensor connector by backprobing. Do not disconnect BARO sensor harness connector. Turn ignition on. Using a DVOM, measure voltage between BARO sensor harness connector terminal No. 2 and ground by backprobing. See «BAROMETRIC PRESSURE SENSOR VOLTAGE OUTPUT»(ref-152075-S09182821832003011300000) table. Turn ignition switch to LOCK position. If voltage is as specified, go to next step. If voltage is not as specified, go to step 7 . BAROMETRIC PRESSURE SENSOR VOLTAGE OUTPUT Altitude - Feet (Meters) Voltage 0 (0) 3.7-4.3 1969 (600) 3.4-4.0 3937 (1200) 3.2-3.8 5906 (1800) 2.9-3.5
3. Check the sensor output voltage at ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) by backprobing. Do not disconnect harness connector. Turn ignition on. Measure voltage between ECM harness connector C-115 terminal No. 85 (M/T) or PCM harness connector C-118 terminal No. 55 (A/T) and ground by backprobing. See «BAROMETRIC PRESSURE SENSOR VOLTAGE OUTPUT»(ref-152075-S09182821832003011300000) table. Turn ignition switch to LOCK position. If voltage is as specified, go to next step. If voltage is not as specified, go to step 6 .
4. Check BARO sensor harness connector and ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 18 . If connectors are okay, go to next step.
5. Using scan tool, check BARO sensor. Turn ignition on. Set scan tool to the data reading mode for data list item 25: BAROMETRIC PRESSURE SENSOR. See «BAROMETRIC PRESSURE SENSOR SPECIFICATIONS»(ref-152075-S24317171992003011300000) table. Turn ignition switch to LOCK position. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) . If sensor is not operating properly, replace ECM or PCM. After replacing ECM or PCM, go to step 18 .
6. Check BARO sensor harness connector and ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connectors are in good condition, repair open circuit or harness damage between BARO sensor harness connector and ECM harness connector C-115 terminal No. 85 (M/T) or PCM harness connector C-118 terminal No. 55 (A/T). After repairs, go to step 18 . If connectors are okay, repair or replace as necessary. After repairs, go to step 18 .
7. Check the sensor supply voltage at BARO sensor harness connector by backprobing. Do not disconnect BARO sensor harness connector. Turn ignition on. Measure voltage between BARO sensor harness connector terminal No. 1 and ground by backprobing. Voltage should be 4.8-5.2 volts. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 12 .
8. Check sensor supply voltage at ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) by backprobing. Do not disconnect harness connector. Turn ignition on. Measure voltage between ECM harness connector C-115 terminal No. 81 (M/T) or PCM harness connector C-118 No. 46 (A/T) and ground by backprobing. Voltage should be 4.8-5.2 volts. Turn ignition switch to LOCK position. If voltage is as specified, go to next step. If voltage is not as specified, go to step 10 .
9. Check BARO sensor harness connector and ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connectors are in good condition, repair wiring harness between BARO sensor harness connector and ECM or PCM harness connector for open circuit or harness damage. After repairs, go to step 18 . If connectors are not in good condition, repair or replace connectors. After repairs, go to step 18 .
10. Check BARO sensor harness connector and ECM or PCM harness connector for damage. Repair or replace as necessary. After repairs, go to step 18 . If connectors are okay, go to next step.
11. Check for short circuit to ground between BARO sensor harness connector terminal No. 1 and ECM harness connector C-115 terminal No. 81 (M/T) or PCM harness connector C-118 terminal No. 46 (A/T). Repair as necessary. After repairs, go to step 18 . If circuit is okay, replace ECM or PCM. After replacing ECM or PCM, go to step 18 .
12. Do not disconnect the BARO sensor harness connector. Turn ignition on. Using DVOM, measure voltage between BARO sensor harness connector terminal No. 5 and ground by backprobing. Voltage should be 0.5 volt or less. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 15 .
13. Check BARO sensor harness connector and ECM harness connector C-119 (M/T) or PCM harness connector C-120 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 18 . If connectors are okay, go to next step.
14. Check for harness damage between BARO sensor harness connector terminal No. 5 and ECM harness connector C-119 terminal No. 40 (M/T) or PCM harness connector C-120 terminal No. 16 (A/T). Repair as necessary. After repairs, go to step 18 . If wiring harness okay, replace ECM or PCM. After replacing ECM or PCM, go to step 18 .
15. Check BARO sensor harness connector for damage. Repair or replace as necessary. After repairs, go to step 18 . If connector is okay, go to next step.
16. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 18 . If connector is okay, go to next step.
17. Check for short circuit to ground and harness damage between BARO sensor harness connector terminal No. 2 and ECM harness connector C-115 terminal No. 85 (M/T) or PCM harness connector C-118 terminal No. 55 (A/T). Repair as necessary. After repairs, go to step 18 . If circuit is okay, replace VAF sensor.
18. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check the DTC. If DTC P0107 is output, repeat diagnosis. If DTC P0107 is not output, inspection is complete.

Check conditions are when 2 seconds or more have passed since the starting sequence was completed. battery voltage is greater than 8 volts. Judgement criteria is when BARO sensor output has continued to be 16 psi (113 kPa) or more about 4000 ft. below sea level for 10 seconds.

Troubleshooting Hints

The most likely causes for this DTC to be set are

1. Barometric pressure sensor failed.
2. Open or shorted barometric pressure sensor circuit or loose connector. ECM failed.
3. ECM (M/T) or PCM (A/T) failed.

1. Using scan tool check BARO sensor. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the data reading mode for data list item 25: BAROMETRIC PRESSURE SENSOR. Check scan tool output. See «BAROMETRIC PRESSURE SENSOR PRESSURE OUTPUT»(ref-152075-S11487061332003011300000) table. Turn ignition switch to LOCK position. If sensor is not operating properly, go to next step. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) . BAROMETRIC PRESSURE SENSOR PRESSURE OUTPUT Altitude - Feet (Meters) Scan Tool Output (kPa) 0 (0) 101 1969 (600) 95 3937 (1200) 88 5906 (1800) 81
2. Do not disconnect BARO sensor harness connector. Turn ignition on. Using a DVOM, measure voltage between BARO sensor harness connector terminal No. 2 and ground by backprobing. See «BAROMETRIC PRESSURE SENSOR VOLTAGE OUTPUT»(ref-152075-S26403374042003011300000) table. If voltage is as specified, go to next step. If voltage is not as specified, go to step 5 . BAROMETRIC PRESSURE SENSOR VOLTAGE OUTPUT Altitude - Feet (Meters) Voltage 0 (0) 3.7-4.3 1969 (600) 3.4-4.0 3937 (1200) 3.2-3.8 5906 (1800) 2.9-3.5
3. Check BARO sensor harness connector and ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 12 . If connectors are okay, go to next step.
4. Turn ignition on. Using scan tool, check BARO sensor. Set scan tool to the data reading mode for data list item 25: BAROMETRIC PRESSURE SENSOR. Check scan tool output. See «BAROMETRIC PRESSURE SENSOR PRESSURE OUTPUT»(ref-152075-S11487061332003011300000) table. If sensor is not operating properly, replace ECM or PCM. After replacing ECM or PCM, go to step 12 . If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
5. Do not disconnect BARO sensor. Turn ignition on. Using DVOM, measure voltage between BARO sensor harness connector terminal No. 1 and ground by backprobing. Voltage reading should be 4.8-5.2 volts. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 7 .
6. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 12 . If connector is okay, replace ECM or PCM. After replacing ECM or PCM, go to step 12 .
7. Do not disconnect BARO sensor harness connector. Turn ignition on. Using DVOM, measure voltage between sensor harness connector terminal No. 5 and ground by backprobing. Voltage should be 0.5 volt or less. If voltage is not as specified, go to next step. If voltage is as specified, go to step 10 .
8. Check BARO sensor harness connector and ECM harness connector C-119 (M/T) or PCM harness connector C-120 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 12 . If connector is okay, go to next step.
9. Check for open circuit between BARO sensor harness connector terminal No. 5 and ECM harness connector C-119 terminal No. 40 (M/T) or PCM harness connector C-120 terminal No. 16 (A/T). Repair as necessary, go to step 12 . If wiring harness is okay, replace ECM or PCM. After replacing ECM or PCM, go to step 12 .
10. Check BARO sensor harness connector sensor for damage. Repair or replace as necessary. After repairs, go to step 12 . If connector is okay, go to next step.
11. Check ECM harness connector C-119 (M/T) or PCM harness connector C-120 (A/T) for damage. Repair or replace as necessary. After repairs, go to next step. If connector is okay, replace VAF sensor. After replacing sensor, go to next step.
12. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0108 is output, repeat diagnosis. If DTC P0108 is not output, inspection is complete.

Scheme 5

Check conditions are when engine coolant temperature is more than 169°F (76°C). Check conditions must repeat 5 or more times in order; drive 1, stop 2. Drive 1 is when vehicle speed more than 31 MPH (50 KP/H) lasting a total of more than 60 seconds. Stop 2 is when vehicle speed less than 0.9 MPH (1.5 KP/H) lasting more than 30 seconds. Judgement criteria is when change in the intake air temperature is less than 1.8°F (1°C).

The most likely causes for this DTC to be set are

1. Intake air temperature sensor failed.
2. Open or shorted IAT sensor circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

Note. Intake Air Temperature (IAT) sensor is part of Volume Airflow (VAF) sensor and cannot be serviced separately.

1. Using scan tool, check intake air temperature sensor. Remove the air intake hose from the VAF sensor. Turn ignition on. Set scan tool to the data reading mode for data list item 13: INTAKE AIR TEMPERATURE SENSOR. Heat the sensor using a hair drier. The indicated temperature should increase. See «INTAKE AIR TEMPERATURE SENSOR VOLTAGE»(ref-152075-S34061535552003011300000) table. Do not allow sensor temperature to increase more than 176°F (80°C). Turn ignition switch to LOCK position. Attach air intake hose. If sensor is operating properly, problem is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) . If sensor is not operating properly, go to next step. INTAKE AIR TEMPERATURE SENSOR VOLTAGE Temperature - °F (°C) Volts 32 (0) 3.2-3.8 68 (20) 2.3-2.9 104 (40) 1.5-2.1 176 (80) 0.4-1.0
2. Disconnect IAT sensor harness connector. Using a DVOM, measure resistance between IAT sensor terminals No. 5 and 6. Measure resistance while heating the sensor using a hair drier. See «INTAKE AIR TEMPERATURE SENSOR RESISTANCE»(ref-152075-S07739483372003011300000) table. If resistance is as specified, go to next step. If resistance is not as specified, replace the VAF sensor. After replacing VAF sensor, go to step 9 . INTAKE AIR TEMPERATURE SENSOR RESISTANCE Temperature - °F (°C) k/Ohms -4 (-20) 13-17 32 (0) 5.3-6.7 68 (20) 2.3-3.0 104 (40) 1.0-1.5 140 (60) 0.6-0.8 176 (80) 0.3-0.4
3. Check IAT sensor harness connector for damage. Repair or replace as necessary. After repairs, go to step 9 . If connector is in good condition, go to next step.
4. Disconnect IAT sensor harness connector. Check for resistance between ground and IAT sensor harness connector terminal No. 5. Resistance should be less than 2 ohms. If resistance is not as specified, go to next step. If continuity is as specified, go to step 7 .
5. Check ECM harness connector C-119 (M/T) or PCM harness connector C-120 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 9 . If connector is okay, go to next step.
6. Check for open circuit and harness damage between IAT sensor connector and ECM harness connector C-119 (M/T) or PCM harness connector C-120 (A/T). Repair as necessary. After repairs, go to step 9 . If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 9 .
7. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 9 . If connector is in good condition, go to next step.
8. Check for open circuit and harness damage between IAT sensor harness connector and ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T). Repair as necessary. After repairs, go to next step. If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to next step.
9. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0111 is output, repeat diagnosis. If DTC P0111 is not output, inspection is complete.

Check conditions are when 2 seconds or more have passed since the starting sequence was completed. Judgement criteria is when IAT sensor output voltage has continued to be 0.2 volt or less, corresponding to an air intake temperature of 239°F (115°C) or more for 2 seconds.

The most likely causes for this DTC to be set are

1. Open or shorted IAT sensor circuit or loose connector.
2. IAT sensor failed.
3. ECM (M/T) or PCM (A/T) failed.

1. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the data reading mode for data list item 13: INTAKE AIR TEMPERATURE SENSOR. The intake air temperature and temperature shown with the scan tool should approximately match. If IAT sensor is not operating properly, go to next step. If IAT sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
2. Turn ignition off. Check IAT sensor harness connector for damage. Repair or replace as necessary. After repairs, go to step 6 . If connector is okay, go to next step.
3. Using a DVOM, measure resistance between IAT sensor terminals No. 5 and 6. Resistance should be 300-1000 ohms. If resistance is as specified, go to next step. If resistance is not as specified, replace the VAF sensor. After replacing VAF sensor, go to step 6 .
4. Check for short circuit to ground between IAT sensor harness connector and ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T). Repair as necessary. After repairs, go to step 6 . If circuit is okay, go to next step.
5. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. Repair or replace as necessary. After repairs, go to next step. If connector is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to next step.
6. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0112 is output, repeat diagnosis. If DTC P0112 is not output, inspection is complete.

Check conditions are when 2 seconds or more have passed since the starting sequence was completed. Judgement criteria is when IAT sensor output voltage has continued to be 4.5 volts or more, corresponding to an air intake temperature of -40°F (-40°C) or less for 2 seconds.

The most likely causes for this DTC to be set are

1. IAT sensor failed.
2. Open or shorted IAT sensor circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

1. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the data reading mode for data list item 13: INTAKE AIR TEMPERATURE SENSOR. The intake air temperature and temperature shown with the scan tool should approximately match. If sensor is not operating properly, go to next step. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
2. Turn ignition off. Check IAT sensor harness connector for damage. Repair or replace as necessary. After repairs, go step 11 . If connector is okay, go to next step.
3. Disconnect IAT sensor harness connector. Using a DVOM, measure resistance between IAT sensor terminals No. 5 and 6. There resistance should be 300-1000 ohms. If resistance is as specified, go to next step. If resistance is not as specified, replace the VAF sensor. After replacing VAF sensor, go to step 11 .
4. Turn ignition on. Measure voltage between IAT sensor harness connector terminal No. 6 and ground. Voltage should be 4.5-4.9 volts. If voltage is not as specified, go to next step. If voltage is as specified, go to step 8 .
5. Turn ignition off. Do not disconnect the ECM or PCM harness connectors. Disconnect IAT sensor harness connector. Using DVOM connected to ground, backprobe ECM harness connector terminal No. 72 (M/T) or PCM harness connector terminal No. 64 (A/T). Voltage should be 4.5-4.9 volts. Turn ignition switch to LOCK position. If voltage is as specified, go to next step. If voltage is not as specified, go to step 7 .
6. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 11 . If connector is okay, repair open in wiring harness between IAT sensor harness connector and ECM or PCM harness connector. After repairs, go to step 11 .
7. Check ECM harness connector C-120 (M/T) or PCM harness connector C-114 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 11 . If connector is okay, replace ECM or PCM. After replacing ECM or PCM, go to step 11 .
8. Disconnect IAT harness connector. Check for continuity between IAT harness connector terminal No. 5 and ground. Resistance should be less than 2 ohms. If continuity is not as specified, go to next step. If continuity is as specified, replace ECM or PCM. After replacing ECM or PCM, go to step 11 .
9. Check ECM harness connector C-119 (M/T) or PCM harness connector C-120 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 11 . If harness connector is okay, go to next step.
10. Check for open circuit between IAT sensor harness connector and ECM harness connector C-105 (M/T) or PCM harness connector C-120 (A/T). Repair as necessary. After repairs, go to next step. If circuit is okay, replace ECM or PCM. After replacing ECM or PCM, go to next step.
11. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0113 is output, repeat diagnosis. If DTC P0113 is not output, inspection is complete.

Scheme 6

Check conditions are when engine coolant temperature was 45°F (7°C) or more immediately before the engine was stopped at the last drive. Engine coolant temperature was 45°F (7°C) or more when the engine started. Judgement criteria is when engine coolant temperature fluctuates within 1.8°F (1°C) after 5 minutes have passed since the engine was started. However, time is not counted if any of the following conditions are met

1. Intake air temperature is 140°F (60°C) or more.
2. Volume airflow sensor output frequency is 70 Hz or less.
3. During fuel shut-off operation. Only one monitor during one drive cycle.

The most likely causes for this DTC to be set are

1. ECT sensor failed.
2. Open or shorted engine coolant temperature sensor circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

1. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the data reading mode for data list item 21: ENGINE COOLANT TEMPERATURE SENSOR. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn ignition switch to LOCK position. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) . If sensor is not operating properly, go to next step.
2. Do not disconnect ECT harness connector. Turn ignition on. Using a DVOM, measure voltage between sensor harness connector terminal No. 1 (Yellow/White wire) and ground by backprobing. See «ENGINE COOLANT TEMPERATURE SENSOR VOLTAGE»(ref-152075-S11837926452003011300000) table. If voltage is as specified, go to next step. If voltage is not as specified, go to step 5 . ENGINE COOLANT TEMPERATURE SENSOR VOLTAGE Temperature - °F (°C) Voltage -4 (-20) 3.9-4.5 32 (0) 3.2-3.8 68 (20) 2.3-2.9 104 (40) 1.3-1.9 140 (60) 0.7-1.3 176 (80) 0.3-0.9
3. Turn ignition off. Check ECT sensor harness connector for damage. Repair or replace as necessary. After repairs, go to step 14 . If connector is okay, go to next step.
4. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the data reading mode for data list item 21: ENGINE COOLANT TEMPERATURE SENSOR. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn ignition switch to LOCK position. If sensor is not operating properly, replace ECM (M/T) or PCM (A/T). After replacing ECM or PCM, go to step 14 . If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
5. Check ECT sensor harness connector for damage. Repair or replace as necessary. After repairs, go to step 14 . If connector is in good condition, go to next step.
6. Disconnect ECT sensor harness connector. Turn ignition on. Measure voltage between ECT sensor harness connector terminal No. 1 (Yellow/White wire) and ground. Voltage should be 4.5-4.9 volts. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 8 .
7. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 14 . If connector is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 14 .
8. Check continuity between ECT sensor terminal No. 2 (Black wire) and ground. Resistance should be less than 2 ohms. If continuity is not as specified, go to next step. If continuity is as specified, go to step 11 .
9. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 at (A/T) for damage. Repair or replace as necessary. After repairs, go to step 14 . If connector is in good condition, go to next step.
10. Check for harness damage between ECT sensor harness connector terminal No. 2 and ECM harness connector C-115 terminal No. 92 (M/T) or PCM harness connector C-118 terminal No. 57 (A/T). Repair as necessary. After repairs, go to step 14 . If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 14 .
11. Check ECT sensor. Disconnect ECT sensor harness connector. Remove ECT sensor from engine. With the temperature sensing portion of engine coolant temperature sensor immersed in hot water, check resistance. See «ENGINE COOLANT TEMPERATURE SENSOR RESISTANCE»(ref-152075-S20391205852003011300000) table. If resistance is as specified, replace ECM or PCM. After replacing ECM or PCM, go to step 14 . If resistance is not as specified, replace ECT sensor. Apply 3M AAD (8731) on the thread section of ECT sensor. Install ECT sensor and tighten to 15-29 ft. lbs. (19-39 N.m). After installing ECT sensor, go to step 14 . ENGINE COOLANT TEMPERATURE SENSOR RESISTANCE Temperature - °F (°C) k/Ohms -4 (-20) 14-17 32 (0) 5.1 -6.5 68 (20) 2.1 -2.7 104 (40) 0.9 - 1.3 140 (60) 0.48 -0.68 176 (80) 0.26 -0.36
12. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 14 . If connector is in good condition, go to next step.
13. Check for harness damage between ECT sensor harness connector terminal No. 1 and ECM harness connector C-115 terminal No. 83 (M/T) or PCM harness connector C-118 terminal No. 44 (A/T). Repair as necessary. After repairs, go to next step. If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to next step.
14. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0116 is output, repeat diagnosis. If DTC P0116 is not output, inspection is complete.

Check conditions are when 2 seconds or more have passed since the staring sequence was completed. Judgement criteria is when ECT sensor output voltage has continued to be 0.1 volt or less, corresponding to a coolant temperature of 284°F (140°C) or more, for 2 seconds.

The most likely causes for this DTC to be set are

1. ECT sensor failed.
2. Open or shorted ECT sensor circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

1. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the data reading mode for data list item 21: ENGINE COOLANT TEMPERATURE SENSOR. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn ignition switch to LOCK position. If sensor is not operating properly, go to next step. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
2. Check ECT sensor harness connector for damage. Repair or replace as necessary. After repairs, go to step 6 . If connector is okay, go to next step.
3. Check for short circuit to ground between ECT sensor harness connector and ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T). Repair as necessary. After repairs, go to step 6 . If circuit is okay, go to next step.
4. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 6 . If connector is okay, go to next step.
5. Check ECT sensor. Disconnect ECT harness connector. See Remove ECT sensor from engine. With the temperature sensing portion of ECT sensor immersed in hot water, check resistance. See «ENGINE COOLANT TEMPERATURE SENSOR RESISTANCE»(ref-152075-S20391205852003011300000) table. If resistance is as specified, replace ECM or PCM. After replacing ECM or PCM, go to next step. If resistance is not as specified, replace the ECT sensor. Apply 3M AAD (8731) on the thread section of sensor. Install the ECT sensor and tighten to 15-29 ft. lbs. (19-39 N.m). After installing ECT sensor, go to next step.
6. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0117 is output, repeat diagnosis. If DTC P0117 is not output, inspection is complete.

Check conditions are when 2 seconds or more have passed since the staring sequence was completed. Judgement criteria is when ECT sensor output voltage has continued to be 4.6 volts or more, corresponding to a coolant temperature of -49°F (-45°C) or less for 2 seconds.

The most likely causes for this DTC to be set are

1. ECT sensor failed.
2. Open or shorted ECT sensor circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

1. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the data reading mode for data list item 21: ENGINE COOLANT TEMPERATURE SENSOR. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn ignition switch to LOCK position. If sensor is not operating properly, go to next step. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
2. Check ECT sensor harness connector for damage. Repair or replace as necessary. After repairs, go to step 11 . If connector is okay, go to next step.
3. Disconnect ECT sensor harness connector. Turn ignition on. Using a DVOM, measure voltage between terminal No. 1 and ground. Voltage should be 4.5-4.9 volts. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 7 .
4. Do not disconnect ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T). Disconnect ECT sensor harness connector. Turn ignition on. Measure voltage between ground and ECM harness connector terminal No. 83 (M/T) or PCM harness connector terminal No. 44 (A/T) by backprobing. Voltage should be 4.5-4.9 volts. Turn ignition switch to LOCK position. If voltage is as specified, go to next step. If voltage is not as specified, go to step 6 .
5. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, repair open circuit in wiring harness between ECT sensor connector and ECM or PCM harness connector. After repairs, go to step 11 . If the connector is not in good condition, repair or replace as necessary. After repairs, go to step 11 .
6. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 11 . If connector is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 11 .
7. Disconnect ECT sensor harness connector. Check continuity between ECT sensor harness connector terminal No. 2 and ground. Resistance should be less than 2 ohms. If continuity is as specified, go to step 10 . If continuity is not as specified, go to next step.
8. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 11 . If connector is okay, go to next step.
9. Check for open circuit between ECT sensor harness connector terminal No. 2 and ECM harness connector C-115 terminal No. 92 (M/T) or PCM harness connector C-118 terminal No. 57 (A/T). Repair as necessary. After repairs, go to step 11 . If wiring harness is in good condition, replace ECM or PCM. After replacing ECM of PCM, go to step 11 .
10. Check the ECT sensor. Disconnect the ECT sensor harness connector. Remove ECT sensor. With the temperature sensing portion of engine coolant temperature sensor immersed in hot water, check resistance. See «ENGINE COOLANT TEMPERATURE SENSOR RESISTANCE»(ref-152075-S20391205852003011300000) table. Apply 3M AAD (8731) on the thread section of the ECT sensor. Install ECT sensor and tighten to 15-29 ft. lbs. (19-39 N.m). If resistance is as specified, replace ECM or PCM. After replacing ECM or PCM, go to next step. If resistance is not as specified, replace the ECT sensor. After replacing sensor, go to next step.
11. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0118 is output, repeat diagnosis. If DTC P0118 is not output, inspection is complete.

Scheme 7

Check conditions are when 2 seconds or more have passed since the starting sequence was completed, engine speed is more than 2000 RPM and volumetric efficiency is more than 60 percent. Judgement criteria is when TP sensor output voltage has continued to be 0.8 volt or less for 2 seconds.

Check conditions are when 2 seconds or more have passed since the staring sequence was completed, engine speed is less than 3000 RPM and volumetric efficiency is less than 30 percent. Judgement criteria is when TP sensor output voltage has continued to be 4.6 volts or more for 2 seconds.

The most likely causes for this DTC to be set are

1. TP sensor failed or misadjusted.
2. Open or shorted TP sensor circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

1. Using scan tool, check throttle position sensor. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the data reading mode for data list item 14: THROTTLE POSITION SENSOR. With throttle valve in idle position, voltage should be 0.335-0.935 volt. With throttle valve in full-open position, voltage should be 4.4-5.3 volts. Turn ignition switch to LOCK position. If sensor is not operating properly, go to next step. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
2. Check throttle position sensor harness connector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 14 .
3. Check throttle position sensor. Using a DVOM, measure resistance between throttle position sensor terminals No. 2 and 3. Standard value is 2-4 k/ohms. Measure resistance between the throttle position sensor terminals No. 1 and 2. Move throttle valve from idle position to full-open position. Resistance should change smoothly in proportion to the opening angle of throttle valve. If resistance is as specified, go to next step. If resistance is not as specified, replace throttle position sensor. Then go to step 14 .
4. Disconnect throttle position sensor harness connector. Turn ignition on. Measure voltage between TP sensor harness connector terminal No. 3 and ground. Voltage should be 4.8-5.2 volts. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 7 .
5. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, go to next step. If the connector is not in good condition, repair or replace as necessary. After repairs, go to step 14 .
6. Check for harness damage between throttle position sensor harness connector terminal No. 3 and ECM harness connector C-115 terminal No. 81 (M/T) or PCM harness connector C-118 terminal No. 46 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 14 . If wiring harness is not in good condition, repair wiring harness. After repairs, go to step 14 .
7. Check continuity at throttle position sensor harness connector. Measure continuity between throttle position sensor harness connector terminal No. 2 and ground. Resistance should be less than 2 ohms. If continuity is not as specified, go to next step. If continuity is as specified, go to step 10 .
8. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 14 .
9. Check for open circuit and harness damage between throttle position sensor harness connector terminal No. 2 and ECM harness connector C-115 terminal No. 92 (M/T) or PCM harness connector C-118 terminal No. 57 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 14 . If wiring harness is not in good condition, repair wiring harness. After repairs, go to step 14 .
10. Check ECM harness connector C-115 (M/T) or PCM harness connectors C-116 and C-118 (A/T) for damage. If connector(s) are in good condition, go to next step. If the connector(s) are not in good condition, repair or replace as necessary. After repairs, go to step 14 .
11. Check for harness damage between throttle position sensor harness connector terminal No. 1 and ECM harness connector C-115 terminal No. 84 (M/T) or PCM harness connector C-116 terminal No. 78 (A/T). If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair wiring harness. After repairs, go to step 14 .
12. Check for misadjusted throttle position sensor. See «THROTTLE POSITION SENSOR»(ref-152064-S06111054012003081800000) in ON-VEHICLE ADJUSTMENTS article. If output voltage is as specified, go to next step. If output voltage is not as specified, adjust it throttle position sensor. After adjusting sensor, go to step 14 .
13. Using scan tool, check throttle position sensor. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the data reading mode for data list item 14: THROTTLE POSITION SENSOR. With throttle valve in idle position, voltage should be 0.335-0.935 volt. With throttle valve in full-open position, voltage should be 4.4-5.3 volts. Turn ignition switch to LOCK position. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) . If sensor is not operating properly, replace ECM or PCM. After replacing ECM or PCM, go to next step.
14. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0121 is output, repeat diagnosis. If DTC P0121 is not output, inspection is complete.

Check conditions are when 2 seconds or more have passed since the starting sequence was completed. Judgement criteria is when TP sensor output voltage has continued to be 0.2 volt or less for 2 seconds.

The most likely causes for this code to set are

1. TP sensor failed or misadjusted.
2. Open or shorted TP sensor circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

1. Using scan tool, check throttle position sensor. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the data reading mode for data list item 14: THROTTLE POSITION SENSOR. With throttle valve in idle position, voltage should be 0.335-0.935 volt. With throttle valve in full-open position, voltage should be 4.4-5.3 volts. Turn ignition switch to LOCK position. If sensor is not operating properly, go to next step. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
2. Check throttle position sensor harness connector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 11 .
3. Check supply voltage at throttle position sensor. Disconnect throttle position sensor harness connector. Turn ignition on. Using a DVOM, measure voltage between throttle position sensor harness connector terminal No. 3 and ground. Voltage should be 4.8-5.2 volts. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 6 .
4. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 11 .
5. Check for open or short circuit to ground between throttle position sensor harness connector terminal No. 3 and ECM harness connector C-115 terminal No. 81 or PCM harness connector C-118 terminal No. 46 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 11 . If wiring harness is not in good condition, repair wiring harness. After repairs, go to step 11 .
6. Check throttle position sensor. Disconnect throttle position harness connector. Using DVOM, measure resistance between throttle position sensor terminals No. 2 and 3. Resistance should be 2-4 k/ohms. Measure resistance between throttle position sensor terminals No. 1 and 2. Move throttle valve from idle position to full-open position. Resistance should change smoothly in proportion to the opening angle of throttle valve. If resistance is as specified, go to next step. If resistance is not as specified, replace throttle position sensor. After replacing sensor, go to step 11 .
7. Check ECM harness connector C-115 (M/T) or PCM harness connectors C-116 and C-118 at (A/T) for damage. If connector(s) are in good condition, go to next step. If connector(s) are not in good condition, repair or replace as necessary. After repairs, go to step 11 .
8. Check for open circuit and short circuit to ground between throttle position sensor harness connector terminal No. 1 and ECM harness connector C-115 terminal No. 84 or PCM harness connector C-116 terminal No. 78 (A/T). If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 11 .
9. Check for short circuit to ground between throttle position sensor harness connector and auto-cruise control ECU. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 11 .
10. Using scan tool, check throttle position sensor. Connect scan tool to data link connector. Turn ignition on. Set scan tool to data reading mode for data list item 14: THROTTLE POSITION SENSOR. With throttle valve in idle position, voltage should be 0.335-0.935 volt. With throttle valve in full-open position, voltage should be 4.4-5.3 volts. Turn ignition switch to LOCK position. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) . If sensor is not operating properly, replace ECM or PCM. After replacing ECM or PCM, go to next step.
11. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0122 is output, repeat diagnosis. If DTC P0122 is not output, inspection is complete.

Check conditions are when 2 seconds or more have passed since the starting sequence was completed, engine speed is less than 1000 RPM and volumetric efficiency is less than 60 percent. Judgement criteria is when TP sensor output voltage has continued to be 2 volts or more for 2 seconds.

The most likely causes for this DTC to be set are

1. TP sensor failed or misadjusted.
2. Open or shorted TP sensor circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

1. Using scan tool, check throttle position sensor. Connect scan tool to data link connector. Turn ignition on. Get scan tool to the data reading mode for data list item 14: THROTTLE POSITION SENSOR. With throttle valve in idle position, voltage should be 0.335-0.935 volt. With throttle valve in full-open position, voltage should be 4.4-5.3 volts. Turn ignition switch to LOCK position. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) . If sensor is not operating properly, go to next step.
2. Check throttle position sensor harness connector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 8 .
3. Disconnect throttle position harness connector. Using a DVOM, measure continuity between throttle position sensor terminals No. 1 and ground. Resistance should be less than 2 ohms. If continuity is not as specified, go to next step. If continuity is as specified, go to step 6 .
4. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 8 .
5. Check for open circuit and harness damage between throttle position sensor harness connector terminal No. 2 and ECM harness connector C-115 terminal No. 92 (M/T) or PCM harness connector C-118 terminal No. 57 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 8 . If wiring harness is not in good condition, repair wiring harness. After repairs, go to step 8 .
6. Disconnect throttle position sensor harness connector. Measure resistance between throttle position sensor terminals No. 2 and 3. Resistance should be 2-4 k/ohms. Measure resistance between throttle position sensor terminals No. 1 and 2. Move throttle valve from idle position to full-open position. Resistance should change smoothly in proportion to the opening angle of throttle valve. If resistance is as specified, go to next step. If resistance is not as specified, replace throttle position sensor. After replacing sensor, go to step 8 .
7. Using scan tool, check throttle position sensor. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the data reading mode for data list item 14: THROTTLE POSITION SENSOR. With throttle valve in idle position, voltage should be 0.335-0.935 volt. With throttle valve in full-open position, voltage should be 4.4-5.3 volts. Turn ignition switch to LOCK position. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) . If sensor is not operating properly, replace ECM or PCM. After replacing ECM or PCM, go to next step.
8. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0123 is output, repeat diagnosis. If DTC P0123 is not output, inspection is complete.

Check conditions are when coolant temperature decreases from more than 104°F (40°C) to less than 104°F (40°C). Then engine coolant temperature has continued to be 104°F (40°C) or less for 5 minutes. Judgement criteria is when about 60-300 seconds have passed for the engine coolant temperature to rise about 45°F (70°C) after starting sequence was completed. However, time is not counted when fuel is shut off.

The most likely causes for this DTC to be set are

1. Engine coolant temperature sensor failed.
2. Open or shorted engine coolant temperature sensor circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

1. Using scan tool, check engine coolant temperature sensor. Connect scan tool to data link connector. Turn ignition on. Get scan tool to the data reading mode for data list item 21: ENGINE COOLANT TEMPERATURE SENSOR. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn ignition switch to LOCK position. If sensor is not operating properly, go to next step. If sensor is operating properly, it can be assumed the malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
2. Check the sensor output voltage at engine coolant temperature sensor harness connector by backprobing. Do not disconnect engine coolant temperature harness connector. Turn ignition on. Using a DVOM, measure voltage between engine coolant temperature harness connector terminal No. 1 and ground by backprobing. See «ENGINE COOLANT TEMPERATURE SENSOR VOLTAGE»(ref-152075-S39555533912003011300000) table. Turn ignition switch to LOCK position. If voltage is as specified, go to next step. If voltage is not as specified, go to step 5 . ENGINE COOLANT TEMPERATURE SENSOR VOLTAGE Temperature - °F (°C) Voltage -4 (-20) 3.9-4.5 32 (0) 3.2-3.8 68 (20) 2.3-2.9 104 (40) 1.3-1.9 140 (60) 0.7-1.3 176 (80) 0.3-0.9
3. Check engine coolant temperature sensor harness connector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 14 .
4. Using scan tool, check engine coolant temperature sensor. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the item reading mode for data list item 21: ENGINE COOLANT TEMPERATURE SENSOR. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn ignition switch to LOCK position. If sensor is not operating properly, replace ECM or PCM. After replacing ECM or PCM, go to step 14 . If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
5. Check engine coolant temperature sensor harness connector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 14 .
6. Disconnect engine coolant temperature sensor harness connector. Turn ignition on. Measure voltage between engine coolant temperature harness connector terminal No. 1 and ground. Voltage should be 4.5-4.9 volts. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 8 .
7. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If the connector is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 14 . If connector is in good condition, repair or replace as necessary. After repairs, go to step 14 .
8. Check continuity at engine coolant temperature sensor harness connector. Disconnect engine coolant temperature harness connector. Check continuity between engine coolant temperature harness connector terminal No. 2 and ground. Resistance should be less than 2 ohms. If continuity is as specified, go to step 11 . If continuity is not as specified, go to next step.
9. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 14 .
10. Check for harness damage between engine coolant temperature sensor harness connector terminal No. 2 and ECM harness connector C-115 terminal No. 92 (M/T) or PCM harness connector C-114 terminal No. 57 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 14 . If wiring harness is not in good condition, repair wiring harness. After repairs, go to step 14 .
11. Check engine coolant temperature sensor. Disconnect the engine coolant temperature sensor harness connector. Remove engine coolant temperature sensor. With the temperature sensing portion of engine coolant temperature sensor immersed in hot water, check resistance. See «ENGINE COOLANT TEMPERATURE SENSOR RESISTANCE»(ref-152075-S27649826262003011300000) table. If resistance is as specified, go to next step. If resistance is not as specified, replace engine coolant temperature sensor. Apply 3M AAD (8731) on the thread section of engine coolant temperature sensor. Install engine coolant temperature sensor, and tighten to 15-29 ft. lbs. (19-39 N.m). Then go to step 14 . ENGINE COOLANT TEMPERATURE SENSOR RESISTANCE Temperature - °F (°C) k/Ohms -4 (-20) 14-17 32 (0) 5.1-6.5 68 (20) 2.1-2.7 104 (40) 0.9-1.3 140 (60) 0.48-0.68 176 (80) 0.20-0.36
12. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace connector. After repairs, go to step 14 .
13. Check for harness damage between engine coolant temperature sensor harness connector terminal No. 1 and ECM harness connector C-115 terminal No. 83 (M/T) or PCM harness connector C-114 terminal No. 44 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to next step.
14. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0125 is output, repeat diagnosis. If DTC P0125 is not output, inspection is complete.

Check conditions are when engine coolant temperature is 14-171°F (-10°C to 77°C), difference between engine coolant temperature and intake air temperature is 9°F (5°C) or less, and The volume airflow sensor output frequency is in the low frequency (50-100 Hz or less) state for 490 seconds or less (not extended idling). Judgment criteria is when the time for the engine coolant temperature to rise to 171°F (77°C) takes longer than approximately 10 to 32 minutes.

The most likely causes for this code to be set is a faulty thermostat or ECM (M/T) or PCM (A/T) failure.

Check cooling system. If cooling system is normal, replace ECM or PCM. Ensure DTC P0128 does not reset. If cooling system is not normal, repair cooling system. Ensure DTC P0128 does not reset.

Check conditions are when 3 minutes or more have passed since the starting sequence was completed, heated oxygen sensor (front) signal voltage has continued to be 0.2 volt or lower, engine coolant temperature is higher than 169°F (76°C), engine speed is higher than 1200 RPM, volumetric efficiency is higher than 25% and monitoring time: 7 seconds. Judgement criteria is when input voltage supplied to the ECM (M/T) or PCM (A/T) interface circuit is higher than 4.5 volts when 5 volts is applied to the heated oxygen sensor (front) output line via a resistor. The ECM (M/T) or PCM (A/T) monitors for this condition once during the drive cycle.

The most likely causes for this DTC to be set are

1. Heated oxygen sensor (front) deteriorated.
2. Open circuit in heated oxygen sensor (front) output line.
3. Open circuit in heated oxygen sensor (front) ground line.
4. ECM (M/T) or PCM (A/T) failed.

1. Connect scan tool (MB991502) to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 11, Heated Oxygen Sensor (front). Warm up the engine. When the engine is revved, the output voltage should measure 0.6-1.0 volt. When the engine is idling, the output voltage should repeat 0.4 volt and 0.6 volt to 1.0 volt alternately. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) . If the sensor is malfunctioning, go to the next step.
2. Measure the sensor output voltage at heated oxygen sensor (front) connector B-113 by backprobing. Do not disconnect connector B-113. Start the engine and run at idle. Measure the voltage between terminal No. 4 and ground by backprobing. Warm up the engine. When the engine is at 2,500 RPM, the output voltage should repeat 0 volts to 0.8 volts alternately. Turn the ignition off. If the measured voltage is within the specified range, go to the next step, otherwise, proceed to step 7 .
3. Measure the sensor output voltage at ECM connector C-115 (M/T) or PCM connector C-116 (A/T) by backprobing. Do not disconnect connector C-115 (M/T) or C-116 (A/T). Start the engine and run at idle. Measure the voltage between terminal No. 76 (M/T) or No. 71 (A/T) and ground by backprobing. Warm up the engine. When the engine is at 2,500 RPM, the output voltage should repeat 0 volts to 0.8 volts alternately. Turn the ignition off. If the measured voltage is within the specified range, go to the next step, otherwise, proceed to step 6 .
4. Check connector B-113 at heated oxygen sensor (front) and connector C-115 at ECM (M/T) or connector C-116 at PCM (A/T) for damage. If the connector is in good condition, go to the next step, otherwise, repair or replace the damaged connector and proceed to step 15 .
5. Connect scan tool (MB991502) to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 11, Heated Oxygen Sensor (front). Warm up the engine. When the engine is revved, the output voltage should measure 0.6-1.0 volt. When the engine is idling, the output voltage should repeat 0.4 volts and 0.6 volts to 1.0 volts alternately. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) . If the sensor is malfunctioning, replace the ECM or PCM and proceed to step 15 .
6. Check connector B-113 at heated oxygen sensor (front) and connector C-115 at ECM (M/T) or connector C-116 at PCM (A/T) for damage. If the connector is in good condition, repair harness wire between heated oxygen sensor (front) connector B-113 (terminal No. 4) and ECM connector C-115 (terminal No. 76 - M/T) or PCM connector C-116 (terminal No. 71 - A/T - because of open circuit or harness damage). If the connector is damaged, repair or replace it. Proceed to step 15 .
7. Check connector B-113 at heated oxygen sensor (front) for damage. If the connector is in good condition, go to the next step, otherwise, repair or replace the damaged connector and proceed to step 15 .
8. Check for continuity at heated oxygen sensor (front) harness side connector B-113. Disconnect connector B-113 and measure at the harness side. Check for the continuity between terminal No. 2 and ground. The resistance should be less than 2 ohms. If continuity exists, proceed to step 11 , otherwise, go to the next step.
9. Check connector C-115 at ECM (M/T) or connector C-118 at PCM (A/T) for damage. If the connector is in good condition, go to the next step, otherwise, repair or replace the connector and proceed to step 15 .
10. Check for open circuit and harness damage between heated oxygen sensor (front) connector B-113 (terminal No. 2) and ECM connector C-115 (terminal No. 92 - M/T) or PCM connector C-118 (terminal No. 57 - A/T). If the harness wire is in good condition, replace the ECM or PCM, otherwise, repair the damaged harness wire. Proceed to step 15 .
11. Check connector C-115 at ECM (M/T) or connector C-116 at PCM (A/T) for damage. If the connector is in good condition, go to the next step, otherwise, repair or replace it and proceed to step 15 .
12. Check for harness damage between heated oxygen sensor (front) connector B-113 (terminal No. 2) and ECM connector C-115 (terminal No. 92 - M/T) or PCM connector C-118 (terminal No. 57 - A/T). If the harness wire is in good condition, go to the next step, otherwise, repair it and proceed to step 15 .
13. Check for short circuit to ground and harness damage between heated oxygen sensor (front) connector B-113 (terminal No. 4) and ECM connector C-115 (terminal No. 76 - M/T) or PCM connector C-116 (terminal No. 71 - A/T). If the harness wire is in good condition, go to the next step, otherwise, proceed to step 15 .
14. Check the heated oxygen sensor (front). Disconnect the heated oxygen sensor (front) connector B-113 and connect test harness special tool, (MD998464), to the connector on the heated oxygen sensor (front) side. Warm up the engine until engine coolant reaches 176°F (80°C) or higher. CAUTION: Be very careful when connecting the jumper wires; incorrect connection can damage the heated oxygen sensor (front). Use the jumper wires to connect terminal No. 1 (red clip) to the positive battery terminal and terminal No. 3 (blue clip) to the negative battery terminal. Connect a digital volt meter between terminal No. 2 (black clip) and terminal No. 4 (white clip). While repeatedly revving the engine, measure the heated oxygen sensor (front) output voltage. Standard value: 0.6-1.0 volt. If the voltage is normal, replace the ECM or PCM, otherwise, replace the heated oxygen sensor (front). Go to the next step.
15. Carry out a test with the drive cycle pattern (Other Monitor), see «OTHER MONITOR»(ref-152075-S37595059962003011300000) . Check the diagnostic trouble codes. If DTC P0130 is set, repeat the troubleshooting. If the DTC is absent, the inspection is complete.

Check conditions are when 3 minutes or more have passed since the starting sequence was completed, heated oxygen sensor (front) signal voltage has continued to be 0.2 volts or lower, engine coolant temperature is higher than 169°F (76°C), engine speed is higher than 1,200 RPM, volumetric efficiency is higher than 25%, volume air flow sensor output frequency is 81 Hz or more, at least 20 seconds have passed since fuel shut off control was cancelled, after the ignition is turned on, the changes in the output voltage of the heated oxygen sensor (front) are lower than 0.078 volts and monitoring time: 10 seconds. Judgement criteria is when making the air/fuel ratio 15% richer for 10 seconds does not result in an increase in output voltage from the heated oxygen sensor (front) beyond 0.2 volts and the ECM (M/T) or PCM (A/T) monitors this condition once during the drive cycle.

The most likely causes for this DTC to be set are

1. Heated oxygen sensor (front) deteriorated.
2. Short circuit in heated oxygen sensor (front) output line.
3. ECM (M/T) or PCM (A/T) failed.

1. Connect scan tool (MB991502) to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 11, Heated Oxygen Sensor (front). Warm up the engine. When the engine is revved, the output voltage should measure 0.6-1.0 volt. When the engine is idling, the output voltage should repeat 0.4 volt and 0.6 volt to 1.0 volt alternately. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) . If the sensor is malfunctioning, go to the next step.
2. Check the heated oxygen sensor (front). Disconnect the heated oxygen sensor (front) connector B-113 and connect test harness special tool, (MD998464), to the connector on the heated oxygen sensor (front) side. Warm up the engine until engine coolant is 176°F (80°C) or higher. CAUTION: Be very careful when connecting the jumper wires; incorrect connection can damage the heated oxygen sensor (front). Use the jumper wires to connect terminal No. 1 (red clip) to the positive battery terminal and terminal No. 3 (blue clip) to the negative battery terminal. Connect a digital volt meter between terminal No. 2 (black clip) and terminal No. 4 (white clip). While repeatedly revving the engine, measure the heated oxygen sensor (front) output voltage. Standard value: 0.6-1.0 volt. If the voltage is normal, go to the next step, otherwise, replace the heated oxygen sensor (front) and proceed to step 5 .
3. Check connector B-113 at heated oxygen sensor (front) and connector C-115 at ECM (M/T) or connector C-116 at PCM (A/T) for damage. If the connector is in good condition, go to the next step. If the connector is damaged, repair or replace it and proceed to step 5 .
4. Check for short circuit to ground between heated oxygen sensor (front) connector B-113 (terminal No. 4) and ECM connector C-115 (terminal No. 76 - M/T) or PCM connector C-116 (terminal No. 71 - A/T). If the harness wire is in good condition, replace the ECM or PCM, otherwise, repair the damaged harness wire. Go to the next step.
5. Carry out a test drive with the drive cycle pattern (Other Monitor), see «OTHER MONITOR»(ref-152075-S37595059962003011300000) . Check the diagnostic trouble codes. If DTC P0131 is set, repeat the troubleshooting. If the DTC is absent, the inspection is complete.

Scheme 8

Scheme 9

Check conditions are where 2 seconds or more have passed since the starting sequence was completed. Judgement criteria is where heated oxygen sensor (front) output voltage has continued to be 1.2 volts or higher for 2 seconds.

The most likely causes for this DTC to be set are

1. Heated oxygen sensor (front) deteriorated.
2. Short circuit in heated oxygen sensor (front) output line.
3. ECM (M/T) or PCM (A/T) failed.

1. Using scan tool, check front HO2S. Connect scan tool to data link connector. Start engine and run at idle. Set scan tool to the data reading mode for data list item 11: HEATED OXYGEN SENSOR (FRONT). Warm engine to operating temperature. When engine is revved, the output voltage should be 0.6 to 1.0 volt. When engine is idling, the output voltage should alternate between 0.4 volt or less and 0.6 to 1.0 volt. Turn ignition switch to LOCK position. If sensor is not operating properly, go to next step. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000).
2. Check sensor output voltage at heated oxygen sensor (front) harness connector by backprobing. Do not disconnect the heated oxygen sensor (front) harness connector. Start engine and run at idle. Using a DVOM, measure voltage between heated oxygen sensor harness connector terminal No. 4 and ground by backprobing. Warm engine to operating temperature. When engine is 2500 RPM, the output voltage should alternate between 0-0.8 volt. Turn ignition switch to LOCK position. If voltage is as specified, go to next step. If voltage is not as specified, go to step 7.
3. Check sensor output voltage at ECM harness connector C-115 (M/T) or PCM harness connector C-116 (A/T) by backprobing. Do not disconnect the ECM or PCM harness connectors. Start and operate engine at idle. Measure voltage between ECM harness connector terminal No. 76 (M/T) or PCM harness connector No. 71 (A/T) and ground by backprobing. Warm engine to operating temperature. When engine is 2500 RPM, the output voltage should alternate between 0-0.8 volt. Turn ignition switch to LOCK position. If voltage is as specified, go to next step. If voltage is not as specified, go to step 6.
4. Check for damage in heated oxygen sensor (front) harness connector and ECM or PCM harness connector. If connector(s) are in good condition, go to next step. If connectors are not in good condition, repair or replace connector. After repairs, go to step 15.
5. Using scan tool, check heated oxygen sensor (front). Connect scan tool to data link connector. Start and operate engine at idle. Set scan tool to the data reading mode for data list item 11: HEATED OXYGEN SENSOR (FRONT). Warm engine to operating temperature. When engine is revved, the output voltage should be 0.6 to 1.0 volt. When engine is idling, the output voltage should alternate between 0.4 volt or less and 0.6 to 1.0 volt. Turn ignition switch to LOCK position. If the sensor is not operating properly, replace ECM or PCM. After replacing ECM or PCM, go to step 15. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000).
6. Check heated oxygen sensor (front) harness connector and connector ECM harness connector C-115 (M/T) or PCM harness connector C-116 (A/T) for damage. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 15. If connector is in good condition, repair open circuit or damage to wiring harness between heated oxygen sensor (front) harness connector and ECM harness connector C-115 terminal No. 76 (M/T) or PCM harness connector C-116 terminal No. 71 (A/T). After repairs, go to step 15.
7. Check heated oxygen sensor (front) harness connector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 15.
8. Disconnect heated oxygen sensor (front) harness connector. Check continuity between sensor harness connector terminal No. 2 and ground. Resistance should be less than 2 ohms. If continuity is as specified, go to step 11. If continuity is not as specified, go to next step.
9. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 15.
10. Check for open circuit and harness damage between heated oxygen sensor (front) harness connector terminal No. 2 and ECM harness connector C-115 terminal No. 92 (M/T) or PCM harness connector C-118 terminal No. 57 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 15. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 15.
11. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 15.
12. Check for harness damage between heated oxygen sensor (front) harness connector terminal No. 2 and ECM harness connector C-115 terminal No. 92 (M/T) or PCM harness connector C-118 terminal No. 57 (A/T). If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 15.
13. Check for short circuit to ground and harness damage between heated oxygen sensor (front) harness connector terminal No. 4 and ECM harness connector C-115 terminal No. 76 (M/T) or PCM harness connector C-116 terminal No. 71 (A/T). If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 15.
14. Disconnect heated oxygen sensor (front) harness connector. Connect test harness tool to the heated oxygen sensor (front) side. Warm up engine until engine coolant temperature is 176°F (80°C) or more. Use jumper wires to connect terminal No. 1 (Red clip) to the positive battery terminal and terminal No. 3 (Blue clip) to the negative battery terminal. (Scheme 10) Connect a DVOM between terminal No. 2 (Black clip) and terminal No. 4 (White clip). While repeatedly revving the engine, measure the heated oxygen sensor (front) output voltage. Standard value is 0.6-1.0 volt. If voltage is as specified, replace ECM or PCM. After replacing ECM or PCM, go to next step. If voltage is not as specified, replace heated oxygen sensor (front). After replacing sensor, go to next step.
15. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. Refer to «HEATED OXYGEN SENSOR MONITOR»(ref-152075-S31732035972003011300000) and «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0132 is output, repeat diagnosis. If DTC P0132 is not output, inspection is complete.

Check conditions are when engine coolant temperature is greater than 122°F (50°C), engine speed is 1200-3000 RPM, volumetric efficiency is 20-60 percent, vehicle is under closed loop air/fuel control, the throttle valve is open, short-term fuel trim is more than -25 and less than 25 percent and more than 2 seconds have elapsed after the above mentioned conditions have been met. Monitoring time is 10 seconds by 5 times. Judgment criteria is when the heated oxygen sensor (front) sends "lean" and "rich" signals alternately 10 times or less for 10 seconds.

If the sensor switch time is longer than the judgment criteria due to the MUT-II OBD-II test Mode - H02S Test Results, it is assumed that the heated oxygen sensor has deteriorated. If it is short, it is assumed that the harness is damaged or has a short circuit. If the heated oxygen sensor signal voltage has not changed even once (lean/rich) after the DTC was erased, the sensor switch time will display as zero seconds.

The most likely causes for this DTC to be set are

1. Heated oxygen sensor (front) deteriorated.
2. ECM (M/T) or PCM (A/T) failed.

1. Using scan tool, check heated oxygen sensor (front). Connect scan tool to data link connector. Start and operate engine at idle. Set scan tool to the data reading mode for data list item 11: HEATED OXYGEN SENSOR (FRONT). Warm engine to operating temperature. With engine at 2500 RPM, output voltage should alternate between zero volt and 0.6-1.0 volt. Turn ignition switch to LOCK position. If sensor is not operating properly, replace heated oxygen sensor (front). After replacing sensor, go to next step. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
2. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0133 is output, repeat diagnosis. If DTC P0133 is not output, inspection is complete.

Check conditions are when 30 seconds or more have passed since the starting sequence was completed, engine coolant temperature is more than 169°F (76°C), engine speed is at more than 1200 RPM, volumetric efficiency is more than 30 percent, and throttle position sensor output voltage is less than 3.6 volts. Check conditions are not met when fuel is being shut off. Monitoring time is 30 seconds. Judgment criteria is when heated oxygen sensor (front) output voltage does not get across 0.5 volt within about 30 seconds.

The most likely causes for this DTC to be set are

1. ECM (M/T) or PCM (A/T) failed.
2. Heated oxygen sensor (front) deteriorated.
3. Open circuit in heated oxygen sensor (front) output line.
4. Open circuit in heated oxygen sensor (front) ground line.
5. Heated oxygen sensor (rear) deteriorated.

When the heated oxygen sensor (front) begins to deteriorate, the heated oxygen sensor output voltage will deviate from the voltage when the sensor was new (normally 0.5 volt at stoichiometric ratio). This deviation will be corrected by the heated oxygen sensor (rear). If the heated oxygen sensor (rear) responds poorly because it has deteriorated, it will improperly correct the heated oxygen sensor (front). Thus, even when closed loop control is being effected, the fluctuation of the heated oxygen sensor (front) output voltage decreases, without intersecting with 0.5 volt. As a result, there is a possibility of DTC P0134 becoming registered.

1. Using scan tool, check heated oxygen sensor (rear). Connect scan tool to data link connector. Start the engine and run at idle. Set scan tool to the data reading mode for data list item 59: HEATED OXYGEN SENSOR (REAR). Warm engine to operating temperature. When the engine is revved, the output voltage should be 0.6 to 1.0 volt. Turn ignition switch to LOCK position. If the sensor is operating properly, go to next step. If the sensor is not operating properly, refer to «DTC P0137: HEATED OXYGEN SENSOR CIRCUIT LOW VOLTAGE (SENSOR 2)»(ref-152075-S00078317202003011300000), «DTC P0138: HEATED OXYGEN SENSOR CIRCUIT HIGH VOLTAGE (SENSOR 2)»(ref-152075-S21848652232003011300000) and «DTC P0139: HEATED OXYGEN SENSOR CIRCUIT SLOW RESPONSE (SENSOR 2)»(ref-152075-S35773550192003011300000).
2. Check for exhaust leaks. Repair as necessary. After repairs, go to step 12. If no leaks are found, go to next step.
3. Check intake system for any vacuum leak. Repair as necessary. After repairs, go to step 12. If no leaks are found, go to next step.
4. Check heated oxygen sensor (front) harness connector for damage. Repair as necessary. After repairs, go to step 12. If the connector is in good condition, go to next step.
5. Check the heated oxygen sensor (front). Disconnect the heated oxygen sensor (front) harness connector. Connect test harness special tool to the connector on the heated oxygen sensor (front) side. Warm up engine until engine coolant is 176°F (80°C) or greater. Use jumper wires to connect terminal No. 1 (Red clip) to the positive battery terminal and terminal No. 3 (Blue clip) to the negative battery terminal. (Scheme 10) Connect a DVOM between terminal No. 2 (Black clip) and terminal No. 4 (White clip). While repeatedly revving engine, measure heated oxygen sensor (front) output voltage. Standard value is 0.6-1.0 volt. If voltage is as specified, go to next step. If voltage is not as specified, replace heated oxygen sensor (front). After replacing sensor, go to step 12.
6. Check fuel injector harness connectors B-17, B-18, B-20 and B-22 for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12.
7. Check fuel injectors. Disconnect each fuel injector harness connector. Using a DVOM, measure resistance between each fuel injector terminals No. 1 and 2. Standard value is 13-16 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace affected fuel injector. After replacing fuel injector, go to step 12.
8. Check ECM harness connectors C-115 and C-121 (M/T) or PCM harness connectors C-116 and C-120 (A/T) for damage. If connectors are in good condition, go to next step. If connectors are not in good condition, repair or replace as necessary. After repairs, go to step 12.
9. Check for harness damage between heated oxygen sensor (front) harness connector terminal No. 4 and ECM harness connector C-115 terminal No. 76 (M/T) or PCM harness connector C-116 terminal No. 71 (A/T). If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 12.
10. Check for harness damage between injector harness connectors B-17, B-18, B-20 and B-22, and ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T). See «INJECTOR CONTROL CIRCUIT IDENTIFICATION»(ref-152075-S14970028342003011300000) table. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 12.
11. Check fuel pressure. See BASIC DIAGNOSTIC PROCEDURES article. If fuel pressure is normal, replace ECM or PCM. After replacing ECM or PCM, go to next step. If fuel pressure is not normal, repair as necessary. After repairs, go to next step.
12. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0134 is output, repeat diagnosis. If DTC P0134 is not output, inspection is complete.

INJECTOR CONTROL CIRCUIT IDENTIFICATION

Check conditions are when 60 seconds have elapsed from the start of the previous monitoring, engine coolant temperature is greater than 68°F (20°C), heated oxygen sensor (front) heater is on and battery voltage is 11-16 volts. Judgment criteria is when heater current of the heated oxygen sensor (front) heater has continued to be less than 0.16 amp or more than 7.5 amps for 4 seconds.

The most likely causes for this DTC to be set are

1. Open or shorted heated oxygen sensor (front) heater circuit.
2. Open circuit in heated oxygen sensor (front) heater.
3. ECM (M/T) or PCM (A/T) failed.

1. Turn ignition off. Check heated oxygen sensor (front) harness connector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12.
2. Disconnect heated oxygen sensor (front) harness connector. Connect test harness special tool to the connector on the heated oxygen (front) sensor side. (Scheme 10) Measure resistance between heated oxygen sensor connector terminals No. 1 (Red clip) and terminal No. 3 (Blue clip). Standard value is 4.5-8.0 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace heated oxygen sensor (front). After replacing sensor, go to step 12.
3. Turn ignition on. Using a DVOM, measure voltage between heated oxygen sensor (front) terminal No. 1 and ground. Battery voltage should be present. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 5.
4. Check MFI relay connector for damage. MFI relay is located in underhood fuse/relay block. Repair or replace as necessary. After repairs, go to step 12. If connector is in good condition, repair open or short to ground in wiring harness between MFI relay connector terminal No. 4 and heated oxygen sensor (front) harness connector terminal No. 1. After repairs, go to step 12.
5. Check power supply voltage at ECM harness connector C-117 or PCM harness connector C-120 by backprobing. Do not disconnect ECM or PCM harness connectors. Turn ignition on. Check voltage between ground and ECM harness connector terminal No. 60 (M/T) or PCM harness connector terminal No. 3 (A/T) by backprobing. Battery voltage should be present. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 8.
6. Check ECM harness connector C-117 (M/T) or PCM harness connector C-120 (A/T) for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace as necessary. After repairs, go to step 12.
7. Check for circuit for open or short to ground between heated oxygen sensor (front) harness connector terminal No. 3 and ECM harness connector C-117 terminal No. 60 (M/T) or PCM harness connector C-120 terminal No. 3 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 12. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 12.
8. Check ECM harness connector C-117 (M/T) or PCM harness connector C-120 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12.
9. Check for harness damage between MFI relay connector terminal No. 1 and heated oxygen sensor (front) connector terminal No. 1. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 12.
10. Check for harness damage between heated oxygen sensor (front) connector terminal No. 3 and ECM harness connector C-117 terminal No. 60 (M/T) or PCM harness connector C-120 terminal No. 3 (A/T). If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 12.
11. Check the trouble symptoms. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0135 is output, replace ECM or PCM. After replacing ECM or PCM, go to next step. If DTC P0135 is not output, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000).
12. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0135 is output, repeat diagnosis. If DTC P0135 is not output, inspection is complete.

Check conditions are when 3 minutes or more have passed since the starting sequence was completed, heated oxygen sensor (rear) signal voltage has continued to be 0.15 volts or lower, engine coolant temperature is higher than 169°F (76°C), engine speed is higher than 1,200 RPM, volumetric efficiency is higher than 25% and monitoring time: 7 seconds. Judgement criteria is when input voltage supplied to the ECM (M/T) or PCM (A/T) interface circuit is higher than 4.5 volts when 5 volts is applied to the heated oxygen sensor (rear) output line via a resistor and the ECM (M/T) or PCM (A/T) monitors for this condition once during the drive cycle.

The most likely causes for this DTC to be set are

1. Heated oxygen sensor (rear) failed.
2. Open circuit in heated oxygen sensor (rear) output line.
3. Open circuit in heated oxygen sensor (rear) ground line.
4. ECM (M/T) or PCM (A/T) failed.

1. Connect scan tool (MB991502) to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 59, Heated Oxygen Sensor (rear). Warm up the engine. When the engine is revved, the output voltage should repeat 0 volts and 0.6 volts to 1.0 volts alternately. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) . If the sensor is malfunctioning, go to the next step.
2. Measure the sensor output voltage at heated oxygen sensor (rear) connector C-11 by backprobing. Do not disconnect connector C-11. Start the engine and run at idle. Measure the voltage between terminal No. 1 and ground by backprobing. Warm up the engine. When the engine is revved, the output voltage should repeat 0 volts and 0.6 volts to 1.0 volts alternately. Turn the ignition off. If the measured voltage is in the specified range, go to the next step, otherwise, proceed to step 7 .
3. Measure the sensor output voltage at ECM connector C-115 (M/T) or PCM connector C-116 (A/T) by backprobing. Do not disconnect connector C-115 (M/T) or C-116 (A/T). Start the engine and run at idle. Measure the voltage between terminal No. 75 (M/T) or No. 73 (A/T) and ground by backprobing. Warm up the engine. When the engine is at 2,500 RPM, the output voltage should repeat 0 volts and 0.6 volts to 1.0 volts alternately. Turn the ignition off. If the measured voltage is within the specified range, go to the next step, otherwise, proceed to step 6 .
4. Check connector C-11 at heated oxygen sensor (rear) and connector C-115 at ECM (M/T) or connector C-116 at PCM (A/T) for damage. If the connector is in good condition, go to the next step, otherwise, repair or replace the connector and proceed to step 14 .
5. Connect scan tool (MB991502) to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 59, Heated Oxygen Sensor (rear). Warm up the engine. When the engine is revved, the output voltage should repeat 0 volts and 0.6 volts to 1.0 volts alternately. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) . If the sensor is malfunctioning, replace the ECM or PCM and proceed to step 14 .
6. Check connector C-11 at heated oxygen sensor (rear) and connector C-115 at ECM (M/T) or connector C-116 at PCM (A/T) for damage. If the connector is in good condition, repair harness wire between heated oxygen sensor (rear) connector C-11 (terminal No. 1) and ECM connector C-115 (terminal No. 75 - M/T) or PCM connector C-116 (terminal No. 73 - A/T) because of open circuit or harness damage). If the connector is damaged, repair or replace it. Proceed to step 14 .
7. Check connector C-11 at heated oxygen sensor (rear) for damage. If the connector is in good condition, go to the next step. If the connector is damaged, repair or replace it and proceed to step 14 .
8. Check for continuity at heated oxygen sensor (rear) harness side connector C-11. Disconnect connector C-11 and measure at the harness side. Check for the continuity between terminal No. 2 and ground. The resistance should be less than 2 ohms. If continuity exists, proceed to step 11 , otherwise, go to the next step.
9. Check connector C-115 at ECM (M/T) or connector C-118 at PCM (A/T) for damage. If the connector is in good condition, go to the next step. If the connector is damaged, repair or replace it and proceed to step 14 .
10. Check for open circuit and harness damage between heated oxygen sensor (rear) connector C-11 (terminal No. 2) and ECM connector C-115 (terminal No. 92 - M/T) or PCM connector C-118 (terminal No. 57 - A/T). If the harness wire is in good condition, replace the ECM or PCM, otherwise, repair the damaged harness wire. Proceed to step 14 .
11. Check connector C-115 at ECM (M/T) or connector C-116 at PCM (A/T) for damage. If the connector is in good condition, go to the next step, otherwise, repair or replace the damaged connector and proceed to step 14 .
12. Check for harness damage between heated oxygen sensor (rear) connector C-11 (terminal No. 2) and ECM connector C-115 (terminal No. 92 - M/T) or PCM connector C-118 (terminal No. 57 - A/T). If the harness wire is in good condition, go to the next step, otherwise, repair it and proceed to step 14 .
13. Check the heated oxygen sensor (rear). Disconnect the heated oxygen sensor (rear) connector C-11 and connect test harness special tool, (MB991223), to the connector on the heated oxygen sensor (front) side. Warm up the engine until the engine coolant is 176°F (80°C) or higher. CAUTION: Be very careful when connecting the jumper wires; incorrect connection can damage the heated oxygen sensor (rear). Use the jumper wires to connect terminal No. 3 to the positive battery terminal and terminal No. 4 to the negative battery terminal. Connect a digital volt meter between terminal No. 1 and terminal No. 2. While repeatedly revving the engine, measure the heated oxygen sensor (rear) output voltage. Standard value: 0.6-1.0 volt. If the voltage is normal, replace the ECM or PCM. If the voltage is abnormal, replace the heated oxygen sensor (rear). Go to the next step.
14. Carry out a test drive with the drive cycle pattern (Other Monitor), see «OTHER MONITOR»(ref-152075-S37595059962003011300000) . Check the diagnostic trouble codes. If DTC P0136 is set, repeat the troubleshooting. If the DTC is absent, the inspection is complete.

Scheme 10

Scheme 11

Check conditions are when 3 minutes or more have passed since the starting sequence was completed, heated oxygen sensor (rear) signal voltage has continued to be 0.15 volt or less, engine coolant temperature is more than 169°F (76°C), engine speed is more than 1200 RPM, volumetric efficiency is more than 25 percent, volume airflow sensor output frequency is 81 Hz or more, at least 20 seconds have passed since fuel shut off control was canceled, the heated oxygen sensor (front) outputs 0.5 volts or more, and after the ignition switch is turned ON the changes in the output voltage of the heated oxygen sensor (rear) is less than 0.078 volt. Monitoring time is 10 seconds. Judgement criteria is when making the air/fuel ratio 15 percent richer for 10 seconds does not result in raising the heated oxygen sensor (rear) output voltage beyond 0.15 volt. Only one monitor is performed during one drive cycle.

see scheme 15, see scheme 22 and (Scheme 11).

The most likely causes for this DTC to be set are

1. Heated oxygen sensor (rear) failed.
2. Short circuit in heated oxygen sensor (rear) output line.
3. ECM (M/T) or PCM (A/T) failed.

1. Using scan tool, check heated oxygen sensor (rear). Connect scan tool to data link connector. Start and operate engine at idle. Set scan tool to the data reading mode for data list item 59: HEATED OXYGEN SENSOR (REAR). Warm engine to operating temperature. When engine is revved, the output voltage should be 0.6-1.0 volt. Turn ignition switch to LOCK position. If sensor is not operating properly, go to next step. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
2. Check the heated oxygen sensor (rear). Disconnect heated oxygen sensor (rear) harness connector. Connect test harness special tool to the connector on the heated oxygen sensor (front) side. Warm up the engine until engine coolant 176°F (80°C) or greater. Use the jumper wires to connect terminal No. 5 to the positive battery terminal and terminal No. 6 to the negative battery terminal. Connect a DVOM between terminals No. 3 and No. 4. While repeatedly revving the engine, measure the heated oxygen sensor (rear) output voltage. Standard value is 0.6-1.0 volt. If voltage is as specified, go to next step. If voltage is not as specified, replace the heated oxygen sensor (rear). After repairs, go to step 5 .
3. Check heated oxygen sensor (rear) harness connector and ECM harness connector C-115 (M/T) or PCM harness connector C-116 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 5 .
4. Check for short circuit to ground between heated oxygen sensor (rear) harness connector terminal No. 1 and ECM harness connector C-115 terminal No. 75 (M/T) or PCM harness connector C-116 terminal No. 73 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to next step.
5. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0137 is output, repeat diagnosis. If DTC P0137 is not output, inspection is complete.

Check conditions are where 2 seconds or more have passed since the starting sequence was completed. Judgement Criteria is where heated oxygen sensor (rear) output voltage has continued to be 1.2 volts or higher for 2 seconds.

The most likely causes for this DTC to be set are

1. Heated oxygen sensor (rear) failed.
2. Short circuit in heated oxygen sensor (rear) output line
3. ECM (M/T) or PCM (A/T) failed.

1. Using scan tool, check heated oxygen sensor (rear). Connect scan tool to data link connector. Start and operate engine at idle. Set scan tool to the data reading mode for data list item 59: HEATED OXYGEN SENSOR (REAR). Warm engine to operating temperature. When engine is revved, the output voltage should be 0.6-1.0 volt. Turn ignition switch to LOCK position. If sensor is not operating properly, go to next step. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
2. Check the sensor output voltage at heated oxygen sensor (rear) harness connector by backprobing. Do not disconnect sensor harness connector. Start and operate engine at idle. Using a DVOM, measure voltage between sensor harness connector terminal No. 3 and ground by backprobing. Warm engine to operating temperature. When engine is revved, the output voltage should be 0.6-1.0 volt. Turn ignition switch to LOCK position. If voltage is as specified, go to next step. If voltage is not as specified, go to step 7 .
3. Check the sensor output voltage at ECM harness connector C-115 (M/T) or PCM harness connector C-116 (A/T) by backprobing. Do not disconnect the ECM or PCM harness connector. Start and operate engine at idle. Measure voltage between ground ECM harness connector terminal No. 75 (M/T) or PCM harness connector terminal No. 73 (A/T) by backprobing. Warm engine to operating temperature. When engine is at 2500 RPM, the output voltage should alternate between zero volts and 0.6-1.0 volt. Turn ignition switch to LOCK position. If voltage is as specified, go to next step. If voltage is not as specified, go to step 6 .
4. Check heated oxygen sensor (rear) harness connector and ECM or PCM harness connector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 14 .
5. Using scan tool, check heated oxygen sensor (rear). Connect scan tool to data link connector. Start and operate engine at idle. Set scan tool to the data reading mode for data list item 59: HEATED OXYGEN SENSOR (REAR). Warm engine to operating temperature. When engine is revved, the output voltage should be 0.6-1.0 volt. Turn ignition switch to LOCK position. If sensor is not operating properly, replace ECM or PCM. After repairs, go to step 14 . If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
6. Check heated oxygen sensor (rear) harness connector and ECM or PCM harness connector for damage. If connector is in good condition, repair open circuit or damage to wiring harness between heated oxygen sensor (rear) harness connector terminal No. 1 and ECM harness connector C-115 terminal No. 75 or PCM harness connector C-116 terminal No. 73. After repairs, go to step 14 . If connector is not in good condition, repair or replace as necessary. After repairs, go to step 14 .
7. Check connector C-22 at heated oxygen sensor (rear) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 14 .
8. Disconnect heated oxygen sensor (rear) harness connector. Check for continuity between harness connector terminal No. 4 and ground. Resistance should be less than 2 ohms. If continuity is as specified, go to step 11 . If continuity is not as specified, go to next step.
9. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 14 .
10. Check for open circuit and harness damage between heated oxygen sensor (rear) harness connector terminal No. 2 and ECM harness connector C-116 terminal No. 92 (M/T) or PCM harness connector C-118 terminal No. 57 (A/T). If wiring harness is in good condition, replace ECM or PCM. After repairs, go to step 14 . If wiring harness is not in good condition, repair as necessary. After repairs, go to step 14 .
11. Check ECM harness connector C-115 (M/T) or PCM harness connector C-116 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 14 .
12. Check for harness damage between heated oxygen sensor (rear) harness connector terminal No. 4 and ECM harness connector C-115 terminal No. 92 (M/T) or PCM harness connector C-118 terminal No. 57 (A/T). If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 14 .
13. Check the heated oxygen sensor (rear). Disconnect heated oxygen sensor (rear) harness connector and connect test harness tool to the connector on the heated oxygen sensor (front) side. Warm up engine until engine coolant is 176°F (80°C) or greater. Use the jumper wires to connect terminal No. 5 to the positive battery terminal and terminal No. 6 to the negative battery terminal. Connect a DVOM between terminals No. 3 and No. 4. While repeatedly revving the engine, measure the heated oxygen sensor (rear) output voltage. Standard value is 0.6-1.0 volt. If voltage is as specified, replace ECM or PCM. After replacing ECM or PCM, go to next step. If voltage is not as specified, replace the heated oxygen sensor (rear). After replacing sensor, go to next step.
14. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0138 is output, repeat diagnosis. If DTC P0138 is not output, inspection is complete.

Check conditions are when engine coolant temperature is more than 169°F (76°C), the heated oxygen sensor (front) is active and the cumulative volume airflow sensor output frequency is more than 4,000 Hz under the following conditions, repeated 3 or more times: drive 1, stop 2. Drive 1 is when engine speed is more than 1500 RPM, volumetric efficiency is more than 40 percent, vehicle speed is more than 18.7 MPH (30 KP/H), a total of more than 10 seconds have elapsed with the above mentioned conditions, and more than 2 seconds have elapsed with the fuel shut off. Stop 2 is when vehicle speed must be less than 0.9 MPH (1.5 KP/H). Judgement criteria is when change in the output voltage of the heater oxygen sensor (rear) is less than 0.313 volt. Monitoring stops after fuel has been shut off for more than 38 seconds.

The most likely causes for this DTC to be set are

1. Heated oxygen sensor (rear) failed.
2. ECM (M/T) or PCM (A/T) failed.

1. Using scan tool, check heated oxygen sensor (rear). Connect scan tool to data link connector. Start and operate engine at idle. Set scan tool to the data reading mode for data list item 59: HEATED OXYGEN SENSOR (REAR). Warm engine to operating temperature. After increasing the output voltage 0.15 volt or more by revving engine, allow engine to idle. Then confirm that the output voltage reduces to 0.15 volt or less within 3 seconds. Turn ignition switch to LOCK position. If sensor is not operating properly, replace the heated oxygen sensor (rear). After repairs, go to next step. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
2. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0139 is output, repeat diagnosis. If DTC P0139 is not output, inspection is complete.

Check conditions are when 60 seconds have elapsed from the start of the previous monitoring, engine coolant temperature is more than 68°F (20°C), heated oxygen sensor (rear) heater is on and battery voltage is 11-16 volts. Judgment criteria is when heater current of the heated oxygen sensor (rear) heater is less than 0.16 amp or more than 5.0 amps for 4 seconds.

The most likely causes for this DTC to be set are

1. Open or shorted heated oxygen sensor (rear) heater circuit.
2. Open circuit in heated oxygen sensor (rear) heater.
3. ECM (M/T) or PCM (A/T) failed.

1. Check heated oxygen sensor (rear) harness connector for damage. If the connector is in good condition, go to next step. If the connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
2. Disconnect heated oxygen sensor (rear) harness connector. Connect Test Harness (MB991223) to the harness-side of connector. Measure resistance between test harness terminals No. 3 and No. 4. Standard value is 11-18 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace the heated oxygen sensor (rear). After repairs, go to step 12 .
3. Check the power supply voltage at heated oxygen sensor (rear) harness side connector. Disconnect heated oxygen sensor (rear) harness connector. Turn ignition on. Measure voltage between sensor harness connector terminal No. 3 and ground. Battery voltage should be present. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 5 .
4. Check MFI relay connector for damage. MFI relay is located in underhood fuse/relay block. If connector is in good condition, repair open circuit or short circuit to ground in wiring harness between MFI relay connector terminal No. 4 and heated oxygen sensor (rear) harness connector terminal No. 4. After repairs, go to step 12 . If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
5. Do not disconnect ECM harness connector C-117 (M/T) or PCM harness connector C-120 (A/T). Turn ignition on. Measure voltage between ECM harness connector terminal No. 54 (M/T) or PCM harness connector terminal No. 26 (A/T) and ground by backprobing. Battery voltage should be present. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 8 .
6. Check connector ECM harness connector C-117 (M/T) or PCM harness connector C-120 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
7. Check for open circuit or short circuit to ground between heated oxygen sensor (rear) harness connector terminal No. 4 and ECM harness connector C-117 terminal No. 54 (M/T) or PCM harness connector C-120 terminal No. 26 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 12 . If wiring harness is not in good condition, repair as necessary. After repairs, go to step 12 .
8. Check ECM harness connector C-117 (M/T) or PCM harness connector C-120 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
9. Check for harness damage between MFI relay connector terminal No. 4 and heated oxygen sensor (rear) connector terminal No. 5. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 12 .
10. Check for harness damage between heated oxygen sensor (rear) connector terminal No. 6 and ECM harness connector C-117 terminal No. 54 (M/T) or PCM harness connector C-120 terminal No. 26 (A/T). If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 12 .
11. Check trouble symptoms. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0141 is output, replace ECM or PCM. After replacing ECM or PCM, go to next step. If DTC P0141 is not output, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
12. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0141 is output, repeat diagnosis. If DTC P0141 is not output, inspection is complete.

These check conditions apply when engine coolant temperature is less than approximately 212°F (100°C) when the engine is started. Intake air temperature is less than 140°F (60°C) when engine is started. Under the closed-loop air/fuel ratio control. Engine coolant temperature is more than 171°F (77°C). Volume airflow sensor output frequency is 81 Hz or more. Judgment criteria is when long-term fuel trim has continued to be more than 12.5 percent for 5 seconds or short-term fuel trim has continued to be more than 10.0 percent for 5 seconds.

These check conditions apply when engine coolant temperature is less than approximately 212°F (100°C) when the engine is started. Intake air temperature is less than 140°F (60°C) when engine is started. Under the closed loop air/fuel ratio control. Engine coolant temperature is more than 171°F (77°C). Volume airflow sensor output frequency is 81 Hz or less. Judgment criteria is when long-term fuel trim has continued to be more than 12.5 percent for 5 seconds or short-term fuel trim has continued to be more than 15 percent for 5 seconds.

These check conditions apply when engine coolant temperature is more than approximately 212°F (100°C) when the engine is started. Intake air temperature is more than 140°F (60°C) when engine is started. Under the closed loop air/fuel ratio control. Engine coolant temperature is more than 171°F (77°C). Volume airflow sensor output frequency is 81 Hz or more. Judgment criteria is when long-term fuel trim has continued to be more than 12.5 percent for 5 seconds or short-term fuel trim has continued to be more than 20.0 percent for 5 seconds.

These check conditions apply when engine coolant temperature is more than approximately 212°F (100°C) when the engine is started. Intake air temperature is more than 140°F (60°C) when engine is started. Under the closed loop air/fuel ratio control. Engine coolant temperature is more than 171°F (77°C). Volume airflow sensor output frequency is 81 Hz or less. Judgment criteria is when long-term fuel trim has continued to be more than 12.5 percent for 5 seconds or short-term fuel trim has continued to be more than 25.0 percent for 5 seconds.

These check conditions apply when engine coolant temperature is more than 171°F (77°C). Under the closed loop air/fuel ratio control. Judgment criteria is when long-term fuel trim has continued to be 12.5 percent for 5 seconds or short-term fuel trim has continued to be 25.0 percent for 5 seconds.

The most likely causes for this DTC to be set are

1. Volume airflow sensor failed.
2. Injector failed.
3. Incorrect fuel pressure.
4. Air drawn in from gaps in gasket, seals, etc.
5. Heated oxygen sensor failed.
6. Engine coolant temperature sensor failed.
7. Intake air temperature sensor failed.
8. Barometric pressure sensor failed.
9. Use of incorrect or contaminated fuel.
10. ECM (M/T) or PCM (A/T) failed.

1. Check for exhaust leaks. If there are no leaks, go to next step. If there are any leaks, repair as necessary. After repairs, go to step 14 .
2. Check for intake system vacuum leaks. If there are no leaks, go to next step. If there are any leaks, repair as necessary. After repairs, go to step 14 .
3. Using scan tool, check volume airflow sensor. Connect scan tool to data link connector. Start an operate engine at idle. Set scan tool to the data reading mode for data list item 12: VOLUME AIRFLOW SENSOR. Warm up engine to normal operating temperature of 176-205°F (80-96°C). When idling, data should be 20-46 Hz (1.3-3.3 grams per second). When engine speed is 2500 RPM, data should be 70-110 Hz (6.6-10.2 grams per second). Turn ignition switch to LOCK position. If sensor is operating properly, go to next step. If sensor is not operating properly, go to «DTC P0101: VOLUME AIRFLOW CIRCUIT RANGE/PERFORMANCE PROBLEM»(ref-152075-S04050999912003011300000) .
4. Using scan tool, check intake air temperature sensor. Turn ignition on. Set scan tool to the data reading mode for data list item 13: INTAKE AIR TEMPERATURE SENSOR. The intake air temperature and temperature shown with the scan tool should approximately match. Turn ignition switch to LOCK position. If sensor is operating properly, go to next step. If sensor is not operating properly, go to «DTC P0111: INTAKE AIR TEMPERATURE CIRCUIT MALFUNCTION»(ref-152075-S06316939242003011300000) , «DTC 0112: INTAKE AIR TEMPERATURE CIRCUIT LOW INPUT»(ref-152075-S13056179182003011300000) and «DTC P0113: INTAKE AIR TEMPERATURE CIRCUIT HIGH INPUT»(ref-152075-S01455844812003011300000) .
5. Using scan tool, check engine coolant temperature sensor. Turn ignition on. Set scan tool to the data reading mode for data list item 21: ENGINE COOLANT TEMPERATURE SENSOR. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn ignition switch to LOCK position. If sensor is operating properly, go to next step. If sensor is not operating properly, go to «DTC P0116: ENGINE COOLANT TEMPERATURE CIRCUIT RANGE/PERFORMANCE PROBLEM»(ref-152075-S31435005822003011300000) , «DTC P0117: ENGINE COOLANT TEMPERATURE CIRCUIT LOW INPUT»(ref-152075-S27217253502003011300000) or «DTC P0118: ENGINE COOLANT TEMPERATURE CIRCUIT HIGH INPUT»(ref-152075-S28352700202003011300000) .
6. Using scan tool, check barometric pressure sensor. Turn ignition on. Set scan tool to the data reading mode for data list item 25: BAROMETRIC PRESSURE SENSOR. See «BAROMETRIC PRESSURE SENSOR DATA»(ref-152075-S08454384612003011300000) table. Turn ignition switch to LOCK position. If sensor is operating properly, go to next step. If sensor is not operating properly, go to «DTC P0106: BAROMETRIC PRESSURE CIRCUIT RANGE/PERFORMANCE PROBLEM»(ref-152075-S15990922272003011300000) , «DTC P0107: BAROMETRIC PRESSURE CIRCUIT LOW INPUT»(ref-152075-S09609379232003011300000) or «DTC P0108: BAROMETRIC PRESSURE CIRCUIT HIGH INPUT»(ref-152075-S10824287502003011300000) . BAROMETRIC PRESSURE SENSOR DATA Altitude - Feet (Meters) Pressure 0 (0) 101 kPa 1969 (600) 95 kPa 3937 (1200) 88 kPa 5906 (1800) 81 kPa
7. Check fuel injector harness connectors B-17 (Cyl. No. 4), B-18 (Cyl. No. 3), B-20 (Cyl. No. 2) and B-22 (Cyl. No. 1) at injectors for damage. Repair or replace as necessary. After repairs, go to step 14 . If connector is in good condition, go to next step.
8. Check fuel injectors. Disconnect each fuel injector connector. Measure resistance between each injector terminals No. 1 and 2. Standard value is 13-16 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace the injector. After repairs, go to step 14 .
9. Check connector ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 14 .
10. Check for harness damage between fuel injector connector and ECM (M/T) or PCM (A/T) harness connector. See «INJECTOR CONTROL CIRCUIT IDENTIFICATION»(ref-152075-S14970028342003011300000) table. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 14 .
11. Check fuel pressure. If fuel pressure is normal, go to next step. If fuel pressure is not normal, repair or replace as necessary. After repairs, go to step 14 .
12. Check for entry of foreign matter (water, kerosene, etc.) into fuel. If there are no contaminations, go to next step. If there are any contaminations, replace fuel. After replacing fuel, go to step 14 .
13. Replace affected fuel injector. Carry out a test drive with the drive cycle pattern. See «FUEL TRIM MONITOR»(ref-152075-S26427373132003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0171 is output, replace ECM or PCM. After repairs, go to next step. If DTC P0171 is not output, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
14. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «FUEL TRIM MONITOR»(ref-152075-S26427373132003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0171 is output, repeat diagnosis. If DTC P0171 is not output, inspection is complete.

These check conditions are when under the closed loop air/fuel ratio control, the engine coolant temperature is more than 171°F (77°C) and volume airflow sensor output frequency is 81 Hz or more. Judgment criteria is when long-term fuel trim has continued to be less than -12.5 percent for 5 seconds or short-term fuel trim has continued to be less than -6.0 percent for 5 seconds.

These check conditions are when under the closed loop air/fuel ratio control, the engine coolant temperature is more than 171°F (77°C) and volume airflow sensor output frequency is 81 Hz or less. Judgment criteria is when long-term fuel trim has continued to be less than -12.5 percent for 5 seconds or short-term fuel trim has continued to be less than -11.0 percent for 5 seconds.

These check conditions are when engine coolant temperature is more than 171°F (77°C) under the closed loop air/fuel ratio control. Judgment criteria is when long-term fuel trim has continued to be -12.5 percent for 5 seconds or short-term fuel trim has continued to be -25.0 percent for 5 seconds.

The most likely causes for this DTC to be set are

1. Volume airflow sensor failed.
2. Injector failed.
3. Incorrect fuel pressure.
4. Heated oxygen sensor failed.
5. Engine coolant temperature sensor failed.
6. Intake air temperature sensor failed.
7. Barometric pressure sensor failed.
8. Exhaust leak.
9. Use of incorrect or contaminated fuel.
10. ECM (M/T) or PCM (A/T) failed.

1. Using scan tool, check volume airflow sensor. Connect scan tool to data link connector. Start the engine and run at idle. Set scan tool to the data reading mode for data list item 12: VOLUME AIRFLOW SENSOR. Warm up the engine to normal operating temperature. When idling, data should be 12-38 Hz (2.5-5.0 grams per second). When engine is at 2500 RPM, data should be 55-95 Hz (8.5-12.7 grams per second). Turn ignition switch to LOCK position. If the sensor is operating properly, go to next step. If the sensor is not operating properly, refer to «DTC P0101: VOLUME AIRFLOW CIRCUIT RANGE/PERFORMANCE PROBLEM»(ref-152075-S04050999912003011300000) and «DTC P0102: VOLUME AIRFLOW CIRCUIT LOW INPUT»(ref-152075-S28557030102003011300000) .
2. Using scan tool, check intake air temperature sensor. Turn ignition on. Set scan tool to the data reading mode for data list item 13: INTAKE AIR TEMPERATURE SENSOR. The intake air temperature and temperature shown with the scan tool should approximately match. Turn ignition switch to LOCK position. If sensor is operating properly, go to next step. If sensor is not operating properly, refer to «DTC P0111: INTAKE AIR TEMPERATURE CIRCUIT MALFUNCTION»(ref-152075-S06316939242003011300000) , «DTC 0112: INTAKE AIR TEMPERATURE CIRCUIT LOW INPUT»(ref-152075-S13056179182003011300000) and «DTC P0113: INTAKE AIR TEMPERATURE CIRCUIT HIGH INPUT»(ref-152075-S01455844812003011300000) .
3. Using scan tool, check engine coolant temperature sensor. Turn ignition on. Set scan tool to the data reading mode for data list item 21: ENGINE COOLANT TEMPERATURE SENSOR. The engine coolant temperature and temperature shown with the scan tool should approximately match. Turn ignition switch to LOCK position. If sensor is operating properly, go to next step. If sensor is not operating properly, refer to «DTC P0116: ENGINE COOLANT TEMPERATURE CIRCUIT RANGE/PERFORMANCE PROBLEM»(ref-152075-S31435005822003011300000) , «DTC P0117: ENGINE COOLANT TEMPERATURE CIRCUIT LOW INPUT»(ref-152075-S27217253502003011300000) and «DTC P0118: ENGINE COOLANT TEMPERATURE CIRCUIT HIGH INPUT»(ref-152075-S28352700202003011300000) .
4. Using scan tool, check barometric pressure sensor. Turn ignition on. Set scan tool to the data reading mode for data list item 25: BAROMETRIC PRESSURE SENSOR. See «BAROMETRIC PRESSURE SENSOR DATA»(ref-152075-S08454384612003011300000) table. Turn ignition switch to LOCK position. If sensor is operating properly, go to next step. If sensor is not operating properly, refer to «DTC P0106: BAROMETRIC PRESSURE CIRCUIT RANGE/PERFORMANCE PROBLEM»(ref-152075-S15990922272003011300000) , «DTC P0107: BAROMETRIC PRESSURE CIRCUIT LOW INPUT»(ref-152075-S09609379232003011300000) and «DTC P0108: BAROMETRIC PRESSURE CIRCUIT HIGH INPUT»(ref-152075-S10824287502003011300000) .
5. Check fuel injector. Disconnect each injector connector. Measure resistance between fuel injector terminals No. 1 and 2. Standard value is 13-16 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace the injector. After repairs, go to step 8 .
6. Check fuel pressure. If fuel pressure is normal, go to next step. If fuel pressure is not normal, repair or replace as necessary. After repairs, go to step 8 .
7. Replace affected fuel injector. Carry out a test drive with the drive cycle pattern. See «FUEL TRIM MONITOR»(ref-152075-S26427373132003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0172 is output, replace ECM or PCM. After replacing ECM or PCM, go to next step. If DTC P0172 is not output, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
8. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «FUEL TRIM MONITOR»(ref-152075-S26427373132003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0172 is output, repeat diagnosis. If DTC P0172 is not output, inspection is complete.

Scheme 12

Check conditions are when the difference between engine coolant temperature and intake air temperature is 9°F (5°C) or less when the engine is started, engine coolant temperature is 14-97°F (-10°C to 36°C) or more than 140°F (60°C) when engine is started, and maximum vehicle speed is more than 17 MPH (30 KP/H) after the starting sequence has been completed. Judgement criteria is when the fuel temperature and engine coolant temperature is 27°F (15°C) or more when the engine is started.

The most likely causes for this DTC to be set are

1. Fuel temperature sensor failed.
2. Open or shorted fuel temperature sensor circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

If the engine and radiator have been flushed repeatedly when engine coolant temperature was high (or fuel temperature was high), a Diagnostic Trouble Code (DTC) could be output. Because this is not a failure, DTC must be erased. Make sure to test drive vehicle in accordance with drive cycle pattern in order to verify that a DTC will not be output.

1. Using scan tool, check fuel temperature sensor. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the data reading mode for data list item 4A: FUEL TEMPERATURE SENSOR. Data should be approximately the same as the outside temperature when engine is cooled. Turn ignition switch to LOCK position. If sensor is not operating properly, go to next step. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
2. Check fuel temperature sensor harness connector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
3. Disconnect fuel temperature sensor harness connector. Using a DVOM, measure resistance between fuel temperature sensor terminals No. 1 and 3. Standard value is 0.5-12.0 k/ohms. If resistance is as specified, go to next step. If resistance is not as specified, replace fuel temperature sensor. After replacing sensor, go to step 12 .
4. Check for continuity between fuel temperature sensor harness connector terminal No. 1 and ground. Resistance should be less than 2 ohms. If continuity is as specified, go to next step. If continuity is not as specified, repair open circuit or harness damage wiring harness between fuel temperature sensor connector terminal No. 1 and ground. After repairs, go to step 12 .
5. Turn ignition on. Measure voltage between fuel temperature sensor harness connector terminal No. 3 and ground. Voltage should be 4.5-4.9 volts. Turn ignition switch to LOCK position. If voltage is as specified, go to next step. If voltage is not as specified, go to step 10 .
6. Check sensor supply voltage at ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) by backprobing. Do not disconnect ECM or PCM harness connector. Turn ignition on. Measure voltage between terminal ECM harness connector C-115 No. 77 (M/T) or PCM harness connector terminal No. 51 (A/T) and ground by backprobing. See «FUEL TEMPERATURE SENSOR OUTPUT VOLTAGE»(ref-152075-S14913641372003011300000) table. Turn ignition switch to LOCK position. If voltage is as specified, go to next step. If voltage is not as specified, go to step 8 . FUEL TEMPERATURE SENSOR OUTPUT VOLTAGE Temperature - °F (°C) Voltage 32 (0) 2.7-3.1 68 (20) 2.1-2.5 104 (40) 1.6-2.0 176 (80) 0.8-1.2
7. Check ECM harness connector C-115 at ECM (M/T) or PCM harness connector C-118 at PCM (A/T) for damage. If connector is in good condition, check intermediate connectors C-122, C-127 and D-14 for damage. Repair or replace as necessary. After repairs, go to step 12 . If intermediate connectors are in good condition, repair open in wiring harness between fuel gauge unit connector D-14 terminal No. 3 and ECM harness connector C-115 terminal No. 77 (M/T) or PCM harness connector C-118 terminal No. 51 (A/T). After repairs, go to step 12 .
8. Check ECM harness connector C-115 at ECM (M/T) or PCM harness connector C-118 at PCM (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
9. Check for short circuit to ground between fuel gauge unit harness connector D-10 terminal No. 3 and ECM harness connector C-115 terminal No. 77 (M/T) or PCM harness connector C-118 terminal No. 51 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 12 . If wiring harness is not in good condition, repair as necessary. After repairs, go to step 12 .
10. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
11. Check intermediate connectors C-122, C-127 and D-14. Repair or replace as necessary. After repairs, go to next step. If intermediate connectors are okay, check for harness damage between fuel temperature sensor harness connector D-10 terminal No. 3 and ECM harness connector C-115 terminal No. 77 (M/T) or PCM harness connector C-118 terminal No. 51 (A/T). Repair or replace as necessary. After repairs, go to next step. If connectors are okay, replace ECM or PCM. After replacing ECM or PCM, go to next step.
12. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0181 is output, repeat diagnosis. If DTC P0181 is not output, inspection is complete.

Check conditions are when 2 seconds or more have passed since the starting sequence was completed. Judgement criteria is when sensor output voltage has continued to be 0.1 volt or less for 2 seconds.

The most likely causes for this DTC to be set are

1. Fuel temperature sensor failed.
2. Open or shorted fuel temperature sensor circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

1. Using scan tool, check fuel temperature sensor. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the data reading mode for data list item 4A: FUEL TEMPERATURE SENSOR. Data should be approximately the same as the outside temperature when engine is cooled. Turn ignition switch to LOCK position. If sensor is not operating properly, go to next step. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
2. Check fuel temperature sensor. Disconnect fuel temperature sensor harness connector. Using a DVOM, measure resistance between fuel temperature sensor terminals No. 1 and 3. Standard value is 0.5-12.0 k/ohms. If resistance is as specified, go to next step. If resistance is not as specified, replace fuel temperature sensor. After replacing sensor, go to step 5 .
3. Check fuel temperature sensor harness connector and ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 5 .
4. Check for short to ground between fuel sensor harness connector D-10 and ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to next step.
5. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0182 is output, repeat diagnosis. If DTC P0182 is not output, inspection is complete.

Check conditions are when 2 seconds or more have passed since the starting sequence was completed. Judgement criteria is when sensor output voltage has continued to be 4.6 volts or more for 2 seconds.

The most likely causes for this DTC to be set are

1. Fuel temperature sensor failed.
2. Open or short fuel temperature sensor circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

1. Using scan tool, check fuel temperature sensor. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the data reading mode for data list item 4A: FUEL TEMPERATURE SENSOR. Data should be approximately the same as the outside temperature when engine is cooled. Turn ignition switch to LOCK position. If sensor is not operating properly, go to next step. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
2. Check fuel temperature sensor harness connector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 11 .
3. Disconnect fuel temperature sensor harness connector. Using DVOM, measure resistance between fuel temperature sensor terminals No. 1 and 3. Standard value is 0.5-12.0 k/ohms. If resistance is as specified, go to next step. If resistance is not as specified, replace fuel temperature sensor. After replacing sensor, go to step 11 .
4. Disconnect fuel temperature sensor harness connector. Turn ignition on. Measure voltage between fuel temperature sensor harness connector terminal No. 3 and ground. Voltage should be 4.5-4.9 volts Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 8 .
5. Do not disconnect the ECM or PCM harness connector. Disconnect fuel temperature sensor harness connector. Turn ignition on. Measure voltage between ECM harness connector C-115 terminal No. 77 (M/T) or PCM harness connector C-118 terminal No. 51 (A/T) and ground by backprobing. Voltage should be 4.5-4.9 volts. Turn ignition switch to LOCK position. If voltage is as specified, go to next step. If voltage is not as specified, go to step 7 .
6. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 at PCM (A/T) for damage. If connector in good condition, check intermediate connectors C-122, C-127 and D-14 for damage. Repair or replace as necessary. If intermediate connectors are in good condition, repair open circuit between fuel temperature sensor connector D-14 and ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T). After repairs, go to step 11 . If the intermediate connector is not in good condition, repair or replace as necessary. After repairs, go to step 11 .
7. Check ECM harness connector C-115 (A/T) or PCM harness connector C-118 (M/T) for damage. If connector is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 11 . If connector is in good condition, repair or replace as necessary. After repairs, go to step 11 .
8. Disconnect fuel temperature sensor harness connector. Check continuity between ground and sensor harness connector terminal No. 2. Resistance should be less than 2 ohms. If continuity is as specified, go to next step. If continuity is not as specified, repair open circuit or harness damage between fuel temperature sensor harness connector terminal No. 2 and ground. After repairs, go to step 11 .
9. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 11 .
10. Check for open circuit or harness damage between intermediate connectors C-122, C-127 and D-14. Repair or replace as necessary. After repairs, go to next step. If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to next step.
11. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0183 is output, repeat diagnosis. If DTC P0183 is not output, inspection is complete.

Check conditions are when engine speed is less than 1000 RPM and throttle position sensor output voltage is less than 1.16 volts. Judgment criteria is when injector coil surge voltage (battery voltage plus 2 volts) has not been detected for 2 seconds.

The most likely causes for this DTC to be set are

1. Injector failed.
2. Open or shorted injector circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

1. Using scan tool, check injectors. Connect scan tool to data link connector. Start and operate engine at idle. Set scan tool to the actuator testing mode for test items No. 01, 02, 03, 04: INJECTORS. Warm up engine to normal operating temperature. Check if idle state worsens (unstable idling or engine stall) when suspect injector is cut off. Turn ignition switch to LOCK position. If actuator is not operating properly, go to next step. If actuator is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000).
2. Check the connector at injector (B-22 for cylinder No. 1, B-20 for cylinder No. 2, B-18 for cylinder No. 3 and/or B-17 for cylinder No. 4) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 10.
3. Check injector. Disconnect the affected injector connector. Measure resistance between injector terminals No. 1 and 2. Standard value is 13-16 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace injector. After replacing injector, go to step 10.
4. Turn ignition on. Measure voltage between injector harness connector terminal No. 1 and ground. Battery voltage should be present. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 6.
5. Check MFI relay harness connector B-12X for damage. If connector is in good condition, repair open circuit or short circuit to ground in harness between MFI relay connector and affected injector connector. See «INJECTOR POWER CIRCUIT IDENTIFICATION»(ref-152075-S08977844272003011300000) table. Then go to step 10. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 10. INJECTOR POWER CIRCUIT IDENTIFICATION Injector (1) Injector Connector 1 B-22 2 B-20 3 B-18 4 B-17 (1) Power is supplied from MFI relay connector B-12X terminal No. 4 to each injector connector terminal No. 1.
6. Check for harness damage between MFI relay connector and injector connector. See «INJECTOR POWER CIRCUIT IDENTIFICATION»(ref-152075-S08977844272003011300000) table. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 10.
7. Check ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 10.
8. Check for open circuit and short circuit to ground and harness damage between injector connector and ECM harness connector (M/T) or PCM harness connector (A/T). See «INJECTOR CONTROL CIRCUIT IDENTIFICATION»(ref-152075-S34938279202003011300000) table. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 10. INJECTOR CONTROL CIRCUIT IDENTIFICATION Injector No./Connector No. (1) ECM Connector C-121 Terminal No. (M/T) PCM Connector C-120 Terminal No. (A/T) 1/B-22 1 1 2/B-20 14 9 3/B-18 2 24 4/B-17 15 2 (1) Check at injector connector terminal No. 2.
9. Using an oscilloscope, check injector. Disconnect affected injector connector and connect Test Harness Special Tool (MB991348) between harness connector and injector (all terminals should be connected). Connect oscilloscope probe to the injector side connector terminal No. 2. Start engine and operate at idle. Measure waveform. The waveform should show a normal pattern. (Scheme 14) Turn ignition switch to LOCK position. If waveform is not as specified, replace ECM or PCM. After replacing ECM or PCM, go to next step. If waveform is as specified, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000).
10. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTCs P0201, P0202, P0203 and/or P0204 output, repeat diagnosis. If DTCs are not output, inspection is complete.

Check conditions are when engine speed is 500-6000 RPM, engine coolant temperature is more than 14°F (-10°C), intake air temperature is more than 14°F (-10°C), barometric pressure is more than 11 psi (76 kPa) and adaptive learning is complete for the vane which generates a crankshaft position signal. Engine must be running, excluding gear shifting, deceleration, sudden acceleration/deceleration and A/C compressor switching and the throttle deviation is -0.059 v/10 ms to 0.059 v/10 ms. Judgement criteria is when misfire has occurred more frequently than allowed during the last 200 revolutions when the catalyst temperature is more than 1742°F (950°C)or misfire has occurred in 20 or more of the last 1000 revolutions (corresponding to 1.5 times the limit of emission standard). Change in the angular acceleration of the crankshaft is used for misfire detection.

The most likely causes for this DTC to be set are

1. Ignition system related part(s) failed.
2. Faulty crankshaft position sensor.
3. Incorrect air/fuel ratio.
4. Low compression pressure.
5. Skipping of timing belt teeth.
6. EGR system and/or EGR valve failed.
7. ECM (M/T) or PCM (A/T) failed.

1. Using scan tool, check crankshaft position sensor. Connect scan tool to data link connector. Start and operate engine at idle. Set scan tool to the data reading mode for data list item 22: CRANKSHAFT POSITION SENSOR. Check the waveform of the crankshaft position sensor while keeping the engine speed constant. The pulse width should be constant. Turn ignition switch to LOCK position. If the sensor is operating properly, go to next step. If the sensor is not operating properly, go to «DTC P0335: CRANKSHAFT POSITION SENSOR CIRCUIT»(ref-152075-S03911069882003011300000) .
2. Using scan tool, check long-term fuel compensation (trim). Start and operate engine at idle. Set scan tool to the data reading mode for data list item 81, LONG-TERM FUEL COMPENSATION (TRIM). The fuel trim should be between -12.5 and 12.5 when the load is 2500 RPM (during closed loop) after the engine is at operating temperature. Turn ignition switch to LOCK position. If the specification is as specified, go to next step. If the specification is not as specified, go to «DTC P0171: SYSTEM TOO LEAN»(ref-152075-S20495332572003011300000) or «DTC: P0172: SYSTEM TOO RICH»(ref-152075-S11198859442003011300000) .
3. Using scan tool, check short-term fuel compensation (trim). Start and operate engine at idle. Set scan tool to the data reading mode for data list item 82: SHORT-TERM FUEL COMPENSATION (TRIM). The fuel trim should be between -25 and 16.8 when the load is 2500 RPM (during closed loop) after the engine is at operating temperature. Turn ignition switch to LOCK position. If the fuel trim is as specified, go to next step. If the fuel trim is not as specified, go to «DTC P0171: SYSTEM TOO LEAN»(ref-152075-S20495332572003011300000) or «DTC: P0172: SYSTEM TOO RICH»(ref-152075-S11198859442003011300000) .
4. Check each ignition coil for spark. Remove intake manifold. Remove spark plug and connect to spark plug cable. Ground spark plug side electrode securely. When engine is cranked, spark plug should spark. If spark does not exist, go to next step. If spark exists, go to step 7 .
5. Check that spark plug is not burned, insulator is not damaged, and that plug is not seized. If cleaning is required due to carbon deposits, etc., clean using a spark plug cleaner or wire brush, etc. Check spark plug gap using a plug gap gauge, and adjust if not 0.039-0.043" (1.0-1.1 mm). If spark plug is in good condition, go to next step. If spark plug is not in good condition, replace the faulty spark plug. After replacing spark plug, go to step 13 .
6. Check spark plug cable. Check boot and coating for cracks. Measure resistance. Limit is 19 k/ohms maximum. If resistance is as specified, check ignition system. See IGNITION CIRCUIT SYSTEM in SYSTEM & COMPONENT TESTING article. If resistance is not as specified, replace faulty spark plug cable. After replacing spark plug cable, go to step 13 .
7. Disconnect injector connector. Measure resistance between each injector No. 1 and 2. Standard value is 13-16 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace the faulty injector. After replacing injector, go to step 13 .
8. Check injector connector (B-17, B-18, B-20, B-22) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 13 .
9. Check ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 13 .
10. Check for harness damage between injector connector and ECM harness connector (M/T) or PCM harness connector (A/T). See «INJECTOR CONTROL CIRCUIT IDENTIFICATION»(ref-152075-S34938279202003011300000) table. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 13 .
11. Check the following items: Skipped timing belt teeth. Compression. EGR valve. If there are no abnormalities, go to next step. If there are any abnormalities, repair or replace as necessary. After repairs, go to step 13 .
12. Replace fuel injector. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0300 is output, replace the ECM or PCM. After replacing ECM or PCM, go to next step. If DTC P0300 is not output, inspection is complete.
13. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0300 is output, repeat diagnosis. If DTC P0300 is not output, inspection is complete.

Check conditions are when engine speed is 500-6000 RPM, engine coolant temperature is more than 14°F (-10°C), intake air temperature is more than 14°F (-10°C), barometric pressure is 11-15 psi (76-106 kPa), volumetric efficiency is between 30-55 percent and adaptive learning is complete for the vane which generates a crankshaft position signal. It is checked when the engine is running, excluding gear shifting, deceleration, sudden acceleration/deceleration and A/C compressor switching and the throttle deviation is -0.059 v/10 ms to 0.059 v/10 ms. Judgement criteria is when a misfire has occurred more frequently than allowed during the last 200 revolutions, when the catalyst temperature is more than 1742°F (950°C) or misfire has occurred in 20 or more of the last 1000 revolutions (corresponding to 1.5 times the limit of emission standard). A change in the angular acceleration of the crankshaft is used for misfire detection.

The most likely causes for this DTC to be set are

1. Ignition system related part(s) failed.
2. Low compression pressure.
3. Injector failed.
4. ECM (M/T) or PCM (A/T) failed.

1. Check spark plugs. Check that spark plug is not burned, insulator is not damaged, and that spark plug is not seized. If cleaning is required due to carbon deposits, etc., clean using a plug cleaner or wire brush, etc. Check spark plug gap using a plug gap gauge, and adjust if not 0.039-0.043" (1.0-1.1 mm). If spark plug is in good condition, go to next step. If spark plug is not in good condition, replace spark plug. After replacing spark plug, go to step 9.
2. Check spark plug cable. Check cap and coating for cracks. Measure spark plug cable resistance. Maximum resistance is 19 k/ohms. If resistance is as specified, go to next step. If resistance is not as specified, replace spark plug cable. After replacing spark plug cable, go to step 9.
3. Check fuel injector. Disconnect the affected fuel injector connector. Measure resistance between fuel injector terminals No. 1 and 2. Standard value is 13-16 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace fuel injector. After replacing fuel injector, go to step 9.
4. Check connector at affected injector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 9.
5. Check ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T) for damage. see scheme 15 If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 9.
6. Check for harness damage between injector connector and ECM harness connector (M/T) or PCM harness connector (A/T). See «INJECTOR CONTROL CIRCUIT IDENTIFICATION»(ref-152075-S34938279202003011300000) table. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 9.
7. Check engine compression. If there any abnormalities, repair or replace as necessary. After repairs, go to step 9. If there no abnormalities, go to next step.
8. Replace fuel injector. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0301, P0302, P0303 and/or P0304 is output, replace ECM or PCM. After replacing ECM or PCM, go to next step. If DTC P0301, P0302, P0303 and P0304 are not output, inspection is complete.
9. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0301, P0302, P0303 and/or P0304 is output, repeat diagnosis. If no DTCs are output, inspection is complete.

Scheme 13

Check conditions are when 2 seconds or more have passed since the starting sequence was completed and engine speed is more than 2500 RPM. Judgment criteria is when knock sensor output voltage (knock sensor peak voltage in each 1/2 turn of the crankshaft) has not changed more than 0.06 volt in the last consecutive 200 periods.

The most likely causes for this DTC to be set are

1. Knock sensor failed.
2. Open or shorted knock sensor circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

1. Check knock sensor harness connector for damage. Knock sensor is located below intake manifold. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 6 .
2. Disconnect knock sensor harness connector. Check continuity between sensor harness connector terminal No. 2 and ground. Resistance should be less than 2 ohms. If continuity is as specified, go to next step. If continuity is not as specified, repair open circuit or harness damage between knock sensor harness connector terminal No. 2 and ground. After repairs, go to step 6 .
3. Check ECM harness connector C-115 (M/T) or PCM harness connector C-116 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 6 .
4. Check for open circuit, short circuit to ground and harness damage between knock sensor harness connector terminal No. 1 and ECM harness connector C-115 terminal No. 78 (M/T) or PCM harness connector C-116 terminal No. 90 (A/T) If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 6 .
5. Replace knock sensor. Carry out a test drive. Check for DTCs. If DTC P0325 is output, replace ECM or PCM. After replacing ECM or PCM, go to next step. If DTC P0325 is not output, inspection is complete.
6. Using scan tool, check ignition coils and ignition power transistor. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the data reading mode for data list item 44: IGNITION COILS AND IGNITION POWER TRANSISTOR. Ignition timing with knock sensor connector disconnected should retard more than the ignition timing with knock sensor connector connected. Turn ignition switch to LOCK position. If ignition timing changes as specified, inspection is complete. If ignition timing does not change as specified, repeat diagnosis.

Scheme 14

Check condition is when engine is being cranked. Judgment criteria is when crankshaft position sensor output voltage has not changed (no pulse signal is input) for 2 seconds. Check conditions and judgment criteria are when normal signal pattern has not been input for cylinder identification from the crankshaft position sensor signal and camshaft position sensor signal for 2 seconds.

The most likely causes for this DTC to be set are

1. Crankshaft position sensor failed.
2. Open or shorted crankshaft position sensor circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

1. Using scan tool, check crankshaft position sensor. Connect scan tool to data link connector. Start and operate engine at idle. Set scan tool to the data reading mode for data list item 22: CRANKSHAFT POSITION SENSOR. The tachometer and engine speed indicated on scan tool should match. Turn ignition switch to LOCK position. If sensor is not operating properly, go to next step. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000).
2. Using oscilloscope, check crankshaft position sensor. Do not disconnect crankshaft position sensor harness connector. Sensor is located behind crankshaft pulley. Connect oscilloscope probe to terminal No. 3 of crankshaft position sensor by backprobing. Start and operate engine at idle. Check waveform. The waveform should show a normal pattern. (Scheme 17) Turn ignition switch to LOCK position. If waveform is as specified, go to next step. If waveform is not as specified, go to step 5.
3. Check crankshaft position sensor harness connector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 21.
4. Using scan tool, check crankshaft position sensor. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the data reading mode for data list item 22: CRANKSHAFT POSITION SENSOR. The tachometer and engine speed indicated on the scan tool should match. Turn ignition switch to LOCK position. If sensor is not operating properly, replace ECM or PCM. After replacing ECM or PCM, go to step 21. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000).
5. Check crankshaft position sensor harness connector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 21.
6. Disconnect crankshaft position sensor harness connector. Turn ignition on. Measure voltage between crankshaft position sensor harness terminal No. 3 and ground. Voltage should be 4.8-5.2 volts. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 11.
7. Check sensor supply voltage at ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) by backprobing. Do not disconnect ECM or PCM harness connector. Disconnect crankshaft position sensor harness connector. Turn ignition on. Measure voltage between ECM harness connector terminal No. 89 (M/T) or PCM harness connector terminal No. 45 (A/T) and ground by backprobing. Voltage should be 4.8-5.2 volts. Turn ignition switch to LOCK position. If voltage is as specified, go to next step. If voltage is not as specified, go to step 9.
8. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, repair open circuit between crankshaft position sensor harness connector terminal No. 3 and ECM harness connector C-115 terminal No. 89 (M/T) or PCM harness connector C-118 terminal No. 45 (A/T). After repairs, go to step 21. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 21.
9. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 21.
10. Check for short circuit to ground between crankshaft position sensor harness connector terminal No. 3 and ECM harness connector C-115 terminal No. 89 (M/T) or PCM harness connector C-118 terminal No. 45 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 21. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 21.
11. Disconnect crankshaft position sensor harness connector. Turn ignition on. Measure voltage between crankshaft position sensor harness connector terminal No. 3 and ground. Battery voltage should be present. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 13.
12. Check connector B-12X at MFI relay for damage. If connector is in good condition, repair open circuit or short circuit to ground in harness between MFI relay connector B-12X terminal No. 4 and crankshaft position sensor harness connector terminal No. 2. After repairs, go to step 21. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 21.
13. Check continuity between crankshaft position sensor harness connector terminal No. 1 and ground. Resistance should be less than 2 ohms. If resistance is as specified, go to step 16. If resistance is not as specified, go to next step.
14. Check ECM harness connector C-119 (M/T) or PCM harness connector C-120 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 21.
15. Check for open circuit or harness damage between crankshaft position sensor harness connector terminal No. 1 and ECM harness connector C-119 terminal No. 40 (M/T) or PCM harness connector C-120 terminal No. 16 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 21. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 21.
16. Check connector B-12X at MPI relay for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 21.
17. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 21.
18. Check for harness damage between MFI relay B-12X terminal No. 4 and crankshaft position sensor harness connector terminal No. 2. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 21.
19. Check for harness damage between crankshaft position sensor harness connector terminal No. 3 and ECM harness connector C-115 terminal No. 89 (M/T) or PCM harness connector C-118 terminal No. 45 (A/T). If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 21.
20. Check crankshaft position sensor vane. If vane is in good condition, replace crankshaft position sensor. After replacing sensor, go to next step. If vane is not in good condition, repair as necessary. After repairs, go to next step.
21. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0335 is output, repeat diagnosis. If DTC P0335 is not output, inspection is complete.

Scheme 15

Check conditions are when engine speed is more than 50 RPM. Judgment criteria is when camshaft position sensor output voltage has not changed (no pulse signal is input) for 2 seconds.

Check conditions are when engine speed is more than 50 RPM. Judgment criteria is when normal signal pattern has not been input for cylinder identification from the crankshaft position sensor signal and camshaft position sensor signal for 2 seconds.

The most likely causes for this DTC to be set are

1. Camshaft position sensor failed.
2. Open or shorted camshaft position sensor circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

1. Using the oscilloscope, check the camshaft position sensor. Disconnect the camshaft position sensor harness connector and connect Test Harness (MB991348) between connectors. All terminals should be connected. Connect oscilloscope probe to the camshaft position sensor side connector terminal No. 2. Start and operate engine at idle. Check the waveform. The waveform should show a normal pattern. (Scheme 17) Turn ignition switch to LOCK position. If waveform is as specified, go to next step. If waveform is not as specified, go to step 4.
2. Check camshaft position sensor harness connector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 20.
3. Check trouble symptoms. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0340 is output, replace ECM or PCM. After replacing ECM or PCM, go to step 20. If DTC P0340 is not output, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000).
4. Check camshaft position sensor harness connector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 20.
5. Disconnect camshaft position sensor harness connector. Turn ignition on. Measure voltage between sensor harness connector terminal No. 2 and ground. Voltage should be 4.8-5.2 volts. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 10.
6. Do not disconnect ECM or PCM harness connector. Disconnect camshaft position sensor harness connector. Turn ignition on. Measure voltage between ECM harness connector C-115 terminal No. 88 (M/T) or PCM harness connector terminal No. 56 (A/T) and ground by backprobing. Voltage should be 4.8-5.2 volts. Turn ignition switch to LOCK position. If voltage is as specified, go to next step. If voltage is not as specified, go to step 8.
7. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, repair open circuit in wiring harness between camshaft position sensor harness connector terminal No. 2 and ECM harness connector C-115 terminal No. 88 (M/T) or PCM harness connector C-118 terminal No. 56 (A/T). After repairs, go to step 20. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 20.
8. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 20.
9. Check for short circuit to ground between camshaft position sensor harness connector terminal No. 2 and ECM harness connector C-115 terminal No. 88 (M/T) or PCM harness connector C-118 terminal No. 56 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 20. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 20.
10. Disconnect camshaft position sensor harness connector. Turn ignition on. Measure voltage between sensor harness connector terminal No. 3 and ground. Battery voltage should be present. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 12.
11. Check connector B-12X at MFI relay for damage. If connector is in good condition, repair wiring harness between MFI relay connector B-12X terminal No. 4 and camshaft position sensor harness connector terminal No. 3 because of open circuit or short circuit to ground. After repairs, go to step 20. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 20.
12. Disconnect camshaft position sensor harness connector. Check continuity between sensor harness connector terminal No. 1 and ground. Resistance should be less than 2 ohms. If continuity is as specified, go to step 15. If continuity is not as specified, go to next step.
13. Check ECM harness connector C-119 (M/T) or PCM harness connector C-120 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 20.
14. Check for open circuit or harness damage between camshaft position sensor harness connector terminal No. 1 and ECM harness connector C-119 terminal No. 40 (M/T) or PCM harness connector C-120 terminal No. 16 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 20. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 20.
15. Check connector B-12X at MFI relay for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 20.
16. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 20.
17. Check for harness damage between MFI relay connector B-12X terminal No. 4 and camshaft position sensor harness connector terminal No. 3. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 20.
18. Check for harness damage between camshaft position sensor harness connector terminal No. 2 and ECM harness connector C-115 terminal No. 88 (M/T) or PCM harness connector C118 terminal No. 56 (A/T). If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 20.
19. Check camshaft position sensor vane. If vane is in good condition, replace camshaft position sensor. After replacing sensor, go to next step. If vane is not in good condition, repair as necessary. After repairs, go to next step.
20. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0340 is output, repeat diagnosis. If DTC P0340 is not output, inspection is complete.

Scheme 16

Check conditions are when at least 20 seconds have passed since the last monitor was complete, engine coolant temperature is more than 169°F (76°C), engine speed is 1000-1800 RPM (M/T) or 880-1800 RPM (A/T), intake air temperature is more than 32°F (0°C), barometric pressure is more than 11 psi (76 kPa), vehicle speed is more than 0.9 MPH (1.5 KP/H - M/T) or 18.7 MPH (30 KP/H - A/T), and at least 90 seconds have passed since manifold differential pressure sensor output voltage fluctuated 1.5 volts or more. The throttle valve must be closed, volumetric efficiency is less than 15 percent (M/T) or 25 percent (A/T), fuel is being shut off (M/T), and 20 seconds have elapsed from the start of the previous monitoring. Monitoring time is 2 seconds by 3 times. Judgement criteria is when intake manifold pressure fluctuations width is less than 0.50 psi (3.5 kPa) when the EGR solenoid is turned on.

The most likely causes for this DTC to be set are

1. EGR valve does not open.
2. EGR control vacuum is too low.
3. EGR solenoid failed.
4. Open or shorted EGR solenoid circuit or loose connector.
5. Manifold differential pressure sensor failed.
6. ECM (M/T) or PCM (A/T) failed.

1. Check the EGR system. If there are no abnormalities, go to next step. If there are any abnormalities, repair as necessary. After repairs, go to step 3 .
2. Using scan tool, check manifold differential pressure sensor. Connect scan tool to data link connector. Start engine and run at idle. Set scan tool to the data reading mode for data list item 95: MANIFOLD DIFFERENTIAL PRESSURE SENSOR. Warm up the engine to normal operating temperature. Data should be 64-78 kPa with engine idling. Turn ignition switch to LOCK position. If the sensor is operating properly, clean the EGR valve and EGR passage. Then go to next step. If the sensor is not operating properly, go to «DTC P1400: MANIFOLD DIFFERENTIAL PRESSURE SENSOR CIRCUIT MALFUNCTION»(ref-152075-S03631556772003011300000) .
3. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «EGR MONITOR»(ref-152075-S29905502032003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0401 is output, repeat diagnosis. If DTC P0401 is not output, inspection is complete.

Check conditions are when engine is being cranked and battery voltage is 10-16 volts. Judgment criteria is when the EGR solenoid coil surge voltage (battery voltage plus 2 volts) is not detected for 0.2 second. Only one monitor is performed during one drive cycle.

Check conditions are when battery voltage is 10-16 volts, ON duty cycle of the EGR solenoid is 10-90 percent, ON duty cycle of the evaporative emission purge solenoid is zero percent, evaporative emission ventilation solenoid is OFF and more than one second has elapsed after the conditions have been met. Judgment criteria is when the EGR solenoid coil surge voltage (battery voltage plus 2 volts) is not detected for one second and when the EGR solenoid is turned off.

The most likely causes for this DTC to be set are

1. EGR solenoid failed.
2. Open or shorted EGR solenoid circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

1. Using scan tool, check EGR solenoid. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the actuator test mode for item 10: EGR SOLENOID. An operation sound should be heard and vibration should be felt when the EGR solenoid is operated. Turn ignition switch to LOCK position. If solenoid is not operating properly, go to next step. If solenoid is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
2. Check EGR solenoid harness connector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
3. Disconnect EGR solenoid harness connector. Using a DVOM, measure resistance between EGR solenoid terminals No. 1 and 2. Standard value is 29-35 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace the EGR solenoid. Then go to step 12 .
4. Turn ignition on. Measure voltage between EGR solenoid harness connector terminal No. 1 and ground. Battery voltage should be present. Turn ignition switch to LOCK position. If voltage is as specified, go to step 6 . If voltage is not as specified, go to next step.
5. Check connector B-12X at MFI relay for damage. Repair or replace as necessary. After repairs, go to step 12 . If connector is okay, repair open or shorted circuit in harness between MFI relay connector B-12X terminal No. 4 and EGR solenoid harness connector terminal No. 1. After repairs, go to step 12 .
6. Do not disconnect ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T). Turn ignition on. Measure voltage between ECM or PCM harness connector terminal No. 6 and ground by backprobing. Battery voltage should be present. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 9 .
7. Check ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
8. Check for open or short circuit to ground in harness between EGR solenoid harness connector terminal No. 2 and ECM harness connector C-121 terminal No. 6 (M/T) or PCM harness connector C-120 terminal No. 6 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 12 . If wiring harness is not in good condition, repair as necessary. After repairs, go to step 12 .
9. Check ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
10. Check for harness damage between MFI relay connector B-12X terminal No. 4 and EGR solenoid harness connector terminal No. 1. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 12 .
11. Check for harness damage between EGR solenoid harness connector terminal No. 2 and ECM harness connector C-121 terminal No. 6 (M/T) or PCM harness connector C-120 terminal No. 6 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to next step.
12. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0403 is output, repeat diagnosis. If DTC P0403 is not output, inspection is complete.

Check conditions are when engine speed is less than 3000 RPM, volume airflow sensor output frequency is 75-150 Hz, intake air temperature is more than 14°F (-10°C) barometric pressure is more than 11 psi (76 kPa), the throttle valve is open, vehicle is under the closed loop air/fuel ratio control and vehicle speed is 0.93 MPH (1.5 KP/H) or more. Monitoring time is 10 seconds by 7 times, short-term fuel trim is more than -25 percent and less than 25 percent, and the cumulative volume airflow sensor output frequency is more than 4000 Hz. Judgment criteria is when the heated oxygen sensor (rear) signal frequency divided by heated oxygen sensor (front) signal frequency = 0.75 (Federal emission regulation) or 0.8 (California emission regulation) or more.

The most likely causes for this DTC to be set are

1. Catalytic converter deteriorated.
2. Heated oxygen sensor failed.
3. ECM (M/T) or PCM (A/T) failed.

1. Check for exhaust leaks. Repair as necessary. After repairs, go to step 7 . If no leaks are found, go to next step.
2. Connect scan tool to data link connector. Turn ignition on. Set scan tool to check data list item 59: HEATED OXYGEN SENSOR (REAR). Start and operate engine at idle. Warm engine to normal operating temperature. Observe scan tool. When engine is revved up, the output voltage should repeat zero volt and 0.6-1.0 volt alternately. Turn ignition switch to LOCK position. If sensor is operating properly, go to next step. If sensor is not operating properly, refer to «DTC P0137: HEATED OXYGEN SENSOR CIRCUIT LOW VOLTAGE (SENSOR 2)»(ref-152075-S00078317202003011300000) «DTC P0138: HEATED OXYGEN SENSOR CIRCUIT HIGH VOLTAGE (SENSOR 2)»(ref-152075-S21848652232003011300000) and «DTC P0139: HEATED OXYGEN SENSOR CIRCUIT SLOW RESPONSE (SENSOR 2)»(ref-152075-S35773550192003011300000) .
3. Start and operate engine at idle. Set scan tool to check data list item 11: HEATED OXYGEN SENSOR (FRONT). Observe scan tool. When engine is revved, the output voltage should be 0.6-1.0 volt. Turn ignition switch to LOCK position. If sensor is operating properly, go to next step. If sensor is not operating properly, refer to «DTC P0132: HEATED OXYGEN SENSOR CIRCUIT HIGH VOLTAGE (SENSOR 1)»(ref-152075-S06893663362003011300000) , «DTC P0133: HEATED OXYGEN SENSOR CIRCUIT SLOW RESPONSE (SENSOR 1)»(ref-152075-S30718238702003011300000) and «DTC P0134: HEATED OXYGEN SENSOR CIRCUIT NO ACTIVITY DETECTED (SENSOR 1)»(ref-152075-S33085179412003011300000) .
4. Start and operate engine at 2000 RPM. Observe scan tool. Output voltage should be 0.0-0.4 and 0.6-1.0 volt and alternating 15 times or more within 10 seconds. Turn ignition switch to LOCK position. If sensor is operating properly, go to next step. If sensor is not operating properly, replace heated oxygen sensor (front). After replacing sensor, go to step 7 .
5. Test the OBD-II drive cycle. Carry out test drive with the drive cycle pattern. See «CATALYTIC CONVERTER MONITOR»(ref-152075-S12465865892003011300000) and «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0421 is output, replace catalytic converter. After replacing catalytic converter, go to step 7 . If DTC P0421 is not output, inspection is complete.
6. Test the OBD-II drive cycle. Carry out test drive with the drive cycle pattern. See «CATALYTIC CONVERTER MONITOR»(ref-152075-S12465865892003011300000) and «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0421 is output, replace ECM or PCM. After replacing ECM or PCM, go to next step. If DTC P0421 is not output, inspection is complete.
7. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0421 is output, repeat diagnosis. If DTC P0421 is not output, inspection is complete.

Check conditions are when ON duty cycle of the evaporative emission purge solenoid is zero percent and 20 seconds have elapsed from the time the duty cycle of the evaporative emission purge solenoid has turned to zero percent. Judgment criteria is when the pressure in the fuel tank is 0.29 psi (-2 kPa) or less.

The most likely causes for this DTC to be set are

1. Evaporative emission purge solenoid failed.
2. Evaporative emission ventilation solenoid failed.
3. Plugged hose between evaporative emission canister and evaporative emission ventilation solenoid.

1. Using scan tool, check evaporative emission purge solenoid. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the actuator test mode for actuator test item 08: EVAPORATIVE EMISSION PURGE SOLENOID. An operation sound should be heard and vibration should be felt when the evaporative emission purge solenoid is operated. Turn ignition switch to LOCK position. If solenoid is operating properly, go to next step. If solenoid is not operating properly, replace the evaporative emission purge solenoid. Then go to step 4 .
2. Using scan tool, check evaporative emission ventilation solenoid. Turn ignition on. Set scan tool to the actuator test mode for actuator test item 29: EVAPORATIVE EMISSION VENTILATION SOLENOID. An operation sound should be heard and vibration should be felt when the evaporative emission ventilation solenoid is operated. Turn ignition switch to LOCK position. If solenoid is operating properly, go to next step. If solenoid is not operating properly, replace evaporative emission ventilation solenoid. Then go to step 4 .
3. Check for clogging in vent hose and solenoid air filter. Repair or replace as necessary. After repairs, go to next step. If no problem is found, go to «DTC P0451: EVAPORATIVE EMISSION CONTROL SYSTEM PRESSURE SENSOR RANGE/PERFORMANCE»(ref-152075-S38037100852003011300000) , «DTC P0452: EVAPORATIVE EMISSION CONTROL SYSTEM PRESSURE SENSOR LOW INPUT»(ref-152075-S09808013382003011300000) or «DTC P0453: EVAPORATIVE EMISSION CONTROL SYSTEM PRESSURE SENSOR HIGH INPUT»(ref-152075-S30228660102003011300000) .
4. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «EVAP SYSTEM LEAK MONITOR»(ref-152075-S34246869422003011300000) under VERIFYING REPAIRS. Read the DTC. If DTC P0441 is set, repeat diagnosis. If DTC P0441 is not set, diagnosis is complete.

Scheme 17

DTC Set Conditions when remaining fuel amount is 15-40 percent of capacity (fuel level sensor output signal voltage is 1.4-2.4V)

Check Conditions A (at start up) are intake air temperature and engine coolant temperature are 97°F (36°C) or less.

Check Conditions B (for test to run) are fuel temperature is lower than 97°F (36°C) and 800 seconds have elapsed since the engine was started, engine coolant temperature is greater than 140°F (60°C), power steering pressure switch is off, barometric pressure is greater than 11 psi (76 kPa), fuel tank differential pressure sensor output voltage is 1-4 volts and vehicle speed is 12.4 mph (20 KP/H) or more.

Check Conditions C (for test to stop) are intake air temperature is greater than 14°F (-10°C), when evaporative emission purge solenoid and evaporative emission ventilation solenoid are closed, the pressure in the tank is less than 0.065 psi (451 Pa), the pressure fluctuation is less than 0.094 psi (647 Pa), 10 seconds have elapsed from the start of the previous monitoring and the monitoring time: 75-125 seconds.

Judgement criteria is when internal pressure of the fuel tank has changed more than 0.114 psi (785 Pa) in 20 seconds after the tank and vapor line were closed. ECM (M/T) or PCM (A/T) monitors for this condition once during the drive cycle.

DTC Set Conditions when remaining fuel amount is 40-85 percent of capacity (fuel level sensor output signal voltage is 2.4-3.7V)

Check Conditions A (at start up) are intake air temperature and engine coolant temperature are less than 97°F (36°C) when the engine is started.

Check Conditions B (for test to run) are the fuel temperature is less than 97°F (36°C), barometric pressure is greater than 11 psi (76 kPa) and fuel tank differential pressure sensor output voltage is 1-4 volts.

Check Conditions C (for test to stop) are intake air temperature is greater than 14°F (-10°C), engine coolant temperature is greater than 68°F (20°C), when the evaporative emission purge solenoid and evaporative emission ventilation solenoid are closed, the pressure in the fuel tank is less than 0.047 psi (324 Pa), 10 seconds have elapsed from the start of the previous monitoring and monitoring time: 10-14 minutes.

Judgement criteria is when internal pressure of the fuel tank has changed more than 0.285 psi (1.96 kPa) 128 seconds after the purge and ventilation solenoids were closed. The ECM (M/T) or PCM (A/T) monitors for this condition once during drive cycle.

The most likely causes for this DTC to be set are

1. Loose fuel cap.
2. Fuel cap relief pressure is incorrect.
3. Evaporative emission canister seal is faulty.
4. Fuel tank, purge line or vapor line seal failed.
5. Evaporative emission ventilation solenoid failed.
6. Evaporative emission purge solenoid does not seal.

To determine the cause of DTC P0442, a performance test is needed. The performance test uses a mechanical vacuum gauge and scan tool set on the fuel tank differential pressure sensor (TANK PRES SNER 73). The mechanical gauge reading is used to verify scan tool reading. A comparison of the mechanical gauge to scan tool determines the problem in the system. Prior to doing the performance test, ensure that the fuel cap is closed securely. Inspect all EVAP system hoses and tubes for damage.

Note. With this monitor, the ECM (M/T) or PCM (A/T) automatically increases the engine speed to 1600 RPM or more.

Scheme 18

1. Using scan tool, check evaporative emission system monitor test. Ensure transaxle is in Park (A/T) or Neutral (M/T). Connect scan tool to data link connector. Turn ignition on. Erase/clear DTCs using scan tool. Check that fuel cap is securely closed. Tighten until 3 clicks are heard. Start engine. Using scan tool, select SYSTEM TEST, and press YES key. Select EVAP LEAK MON, and press YES key. During the monitor, keep accelerator pedal at idle position. If scan tool displays "EVAP Leak Mon. Completed. Test Passed", malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000). Check for loose filler cap. If scan tool displays "EVAP Leak Mon. Completed. Test Failed And DTCs Set", go to next step. If scan tool displays, "EVAP Leak Mon. Discontinued. Retest Again From First", turn ignition off. Repeat this test procedure.
2. Disconnect hose "C" from the evaporative emission purge solenoid valve. (Scheme 20) Connect a hand-held vacuum pump to the nipple of the evaporative emission purge solenoid valve. Apply pressure on hand vacuum pump, and confirm that vacuum is maintained. If vacuum is maintained, go to next step. If vacuum is not maintained, replace evaporative emission purge solenoid valve. After replacing solenoid valve, go to step 15.
3. Check for leaks in the evaporator line hose "A" to hose "C". Perform leakage test with a hand-held vacuum pump on each hose from hose "A" to hose "C". Replace as necessary. After replacing hose, go to step 15. If hoses are in good condition, go to next step.
4. Connect scan tool to data link connector. Disconnect hose "F" from the evaporative emission canister. Connect hand-held vacuum pump to hose "F". Turn ignition on. Set scan tool to actuator test mode for item actuator test item 29: EVAPORATIVE EMISSION VENTILATION SOLENOID VALVE. When the evaporative emission ventilation solenoid valve is operated, apply pressure on hand-held vacuum pump and confirm that pressure is maintained. Turn ignition switch to LOCK position. Disconnect scan tool. Disconnect the hand vacuum pump, and reconnect hose "F" to evaporative emission canister. If evaporative emission ventilation solenoid valve is in good condition, go to step 6. If evaporative emission ventilation solenoid valve is not in good condition, replace evaporative emission ventilation solenoid valve. After replacing solenoid valve, go to step 15.
5. Check for leaks in evaporator line from hose "F". Replace as necessary. After replacing hose, go to step 15. If hose is okay, replace evaporative emission ventilation solenoid valve. After replacing solenoid valve, go to step 15.
6. Check evaporator line hose "D" for leaks. Replace as necessary. After replacing hose, go to step 15. If hose is okay, go to next step.
7. Disconnect and plug hose "G" from evaporative canister side. Remove fuel filler cap. Connect evaporative emission system Pressure Pump (Miller 6872A) to fuel filler neck. Apply pressure to fuel tank. Observe pressure. If pressure is maintained, go to step 13. If pressure is not maintained, go to next step.
8. Remove fuel filler neck protector. Perform leakage test with a hand-held vacuum pump on each hose from hose "G", "I", "J" and "K". Replace faulty hose(s) as necessary. Reinstall fuel tank and fuel filler neck assembly. After replacing hose(s), go to step 15. If hoses are okay, go to next step.
9. Inspect EVAP check valve "A" (located between hose "I" and "J"). Check valve should pass air only from the direction shown. (Scheme 21) Replace as necessary. After replacing check valve, go to step 15. If check valve is okay, go to next step.
10. Remove fuel tank. See REMOVAL, OVERHAUL & INSTALLATION article. Check for leakage in evaporative system hose "H", "L", "M", "N", "O" and "P". Repair as necessary. After repairs, go to step 15. If hoses are okay, go to next step.
11. Inspect EVAP check valve "B" (located between hose "L", "M" and "O"). (Scheme 21) When you blow through check valve (Step 1), it should pass more air. When you blow through check valve in the other direction (Step 2), it should pass less air. No air should leak from the check valve body. If check valve "B" is in good condition, go to next step. If check valve "B" is not in good condition, replace check valve "B", reinstall fuel tank and fuel filler neck assembly. After replacing check valve, go to step 15.
12. Check for leaks in fuel tank. Visually check for cracks and leaks, etc. Carefully check fuel pump assembly and inner pressure sensor installation section in the fuel tank. Connect an evaporative emission system pressure pump to filler pipe. Plug fuel pump feed nipple, return hose, hose "L" and "H" connected to fuel tank. If these items are not securely plugged here, fuel could leak. Apply pressure with evaporative emission system pressure pump. In the pressurized state, check for the leak by applying soapy water to each section. If fuel tank is in good condition, go to next step. If fuel tank is not in good condition, repair leaky parts or replace fuel tank. Reinstall fuel tank. After reinstalling fuel tank, go to step 15.
13. Using scan tool, check evaporative emission system monitor test. Ensure transaxle is in Park (A/T) or Neutral (M/T). Connect scan tool to data link connector. Turn ignition on. Erase/clear DTCs using scan tool. Check that the fuel cap is securely closed. (Tighten until 3 clicks are heard.) Start engine. Using scan tool, select SYSTEM TEST, and press YES key. Select EVAP LEAK MON, and press YES key. During the monitor, keep accelerator pedal at idle position. When the monitor test starts, the IN PROGRESS item on scan tool will change from NO to YES. Turn ignition switch to LOCK position. Disconnect scan tool. If EVAP LEAK MON. COMPLETED. TEST PASSED is displayed, the evaporative emission system is working properly at this time. Go to next step. If EVAP LEAK MON. COMPLETED. TEST FAILED AND DTCS SET is displayed, replace ECM or PCM. After replacing ECM or PCM, go to next step. If EVAP LEAD MON. DISCONTINUED. RETEST AGAIN FROM THE FIRST is displayed, the monitor was discontinued for a certain reason (vehicle speed input from ECM or PCM, engine speed and engine load deviating from specified range). Turn ignition switch to LOCK position once, and recheck evaporative emission system monitor test.
14. Disconnect hoses "E", "F" and "G" from the evaporative emission canister. Connect hand-held vacuum pump to canister port "E". Plug ports not being tested. Apply pressure to canister. Observe if pressure is maintained. Repeat test to remaining ports. Plug ports not being tested. If pressure is maintained, go to step 13. If pressure is not maintained, replace evaporative emission canister. After replacing canister, go to next step.
15. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «EVAP SYSTEM LEAK MONITOR»(ref-152075-S34246869422003011300000) under VERIFYING REPAIRS. Read DTCs. If DTC P0442 is reset, go to step 1. If DTC P0442 is not reset, diagnosis is complete.

Scheme 19

Check conditions are when engine is being cranked and battery voltage is 10-16 volts. Judgment criteria is when the evaporative emission purge solenoid coil surge voltage (battery voltage plus 2 volts) is not detected for 0.2 second. Only one monitor is performed during one drive cycle.

Check conditions are when more than one second has elapsed after battery voltage is 10-16 volts, on duty cycle of the evaporative emission purge solenoid is 10-90 percent, on duty cycle of the EGR solenoid is zero percent and evaporative emission ventilation solenoid is off. Judgment criteria is when the evaporative emission purge solenoid coil surge voltage (battery voltage plus 2 volts) is not detected for one second. When the evaporative emission purge solenoid is turned off.

The most likely causes for this DTC to be set are

1. Evaporative emission purge solenoid failed.
2. Open or shorted evaporative emission purge solenoid circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

1. Using scan tool, check evaporative emission purge solenoid. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the actuator test mode for actuator test item 08: EVAPORATIVE EMISSION PURGE SOLENOID. An operation sound should be heard and vibration should be felt when the evaporative emission purge solenoid is operated. Turn ignition switch to LOCK position. If solenoid is not operating properly, go to next step. If solenoid is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
2. Check evaporative emission purge solenoid harness connector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
3. Check evaporative emission purge solenoid. Disconnect evaporative emission purge solenoid harness connector. Measure resistance between evaporative emission purge solenoid terminals No. 1 and 2. Standard value is 30-34 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace the evaporative emission purge solenoid. After replacing solenoid, go to step 12 .
4. Disconnect evaporative emission purge solenoid harness connector. Turn ignition on. Measure voltage between harness connector terminal No. 2 and ground. Battery voltage should be present. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 6 .
5. Check connector B-12X at MFI relay for damage. If connector is in good condition, repair open circuit or short circuit to ground in harness between MFI relay connector B-12X terminal No. 4 and evaporative emission purge solenoid harness connector terminal No. 2. After repairs, go to step 12 . If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
6. Do not disconnect ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T). Turn ignition on. Measure voltage between ground and ECM harness connector C121 terminal No. 9 (M/T) or PCM harness connector C120 terminal No. 34 (A/T) and ground by backprobing. Battery voltage should be present. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 9 .
7. Check ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
8. Check for open circuit or short circuit to ground between evaporative emission purge solenoid harness connector terminal No. 1 and ECM harness connector C-121 terminal No. 9 (M/T) or PCM harness connector C-120 terminal No. 34 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 12 . If wiring harness is not in good condition, repair as necessary. After repairs, go to step 12 .
9. Check ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
10. Check for harness damage between MFI relay connector B-12X terminal No. 4 and evaporative emission purge solenoid harness connector terminal No. 2. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 12 .
11. Check for harness damage between evaporative emission purge solenoid connector terminal No. 1 and ECM harness connector C-121 terminal No. 9 (M/T) or PCM harness connector C-120 terminal No. 34 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to next step.
12. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0443 is output, repeat diagnosis. If DTC P0443 is not output, inspection is complete.

Scheme 20

Check condition is when engine is being cranked and battery voltage is 10-16 volts. Judgment criteria is when the evaporative emission ventilation solenoid coil surge voltage (battery voltage plus 2 volts) is not detected for 0.2 second. There is only one monitor during one drive cycle.

Check conditions are when more than one second has elapsed after battery voltage is 10-16 volts, on duty cycle of the evaporative emission purge solenoid is zero percent, on duty cycle of the EGR solenoid is zero percent and evaporative emission ventilation solenoid is on. Judgment criteria is when the evaporative emission ventilation solenoid coil surge voltage (battery voltage plus 2 volts) is not detected for one second. When the evaporative emission ventilation solenoid is turned off.

The most likely causes for this DTC to be set are

1. Evaporative emission ventilation solenoid failed.
2. Open or shorted evaporative emission ventilation solenoid circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

1. Using scan tool, check evaporative emission ventilation solenoid. Connect scan tool to data link connector. Turn ignition on. Set scan tool to actuator test mode for item actuator test item 29: EVAPORATIVE EMISSION VENTILATION SOLENOID. An operation sound should be heard and vibration should be felt when the evaporative emission ventilation solenoid is operated. Turn ignition switch to LOCK position. If solenoid is not operating properly, go to next step. If solenoid is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
2. Check evaporative emission ventilation solenoid harness connector for damage (located under left rear of vehicle). If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
3. Disconnect evaporative emission ventilation solenoid harness connector. Measure resistance between evaporative emission ventilation solenoid harness connector terminals No. 1 and 2. Standard value is 17-21 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace the over vent valve module. Then go to step 12 .
4. Disconnect evaporative emission ventilation solenoid harness connector. Turn ignition on. Measure voltage between solenoid harness terminal No. 2 and ground. Battery voltage should be present. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 6 .
5. Check connector B-12X at MFI relay for damage. If connector in good condition, check intermediate connectors C-105, C-124 and C-128 for damage. Repair or replace as necessary. If connectors are in good condition, repair open circuit or short circuit to ground harness between MFI relay connector B-12X terminal No. 4 and evaporative emission ventilation solenoid harness connector terminal No. 2. After repairs, go to step 12 . If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
6. Do not disconnect ECM harness connector C-117 (M/T) or PCM harness connector C-120 (A/T). Turn ignition on. Measure voltage between ECM harness connector C117 terminal No. 55 (M/T) or PCM harness connector terminal No. 35 (A/T) and ground by backprobing. Battery voltage should be present. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 9 .
7. Check ECM harness connector C-117 (M/T) or PCM harness connector C-120 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
8. Check for open circuit or short circuit to ground between evaporative emission ventilation solenoid harness connector terminal No. 1 and ECM harness connector C-117 terminal No. 55 (M/T) or PCM harness connector C-120 terminal No. 35 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 12 . If wiring harness is not in good condition, repair as necessary. After repairs, go to step 12 .
9. Check ECM harness connector C-117 (M/T) or PCM harness connector C-120 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
10. Check for harness damage between MFI relay connector B-12X terminal No. 4 and evaporative emission ventilation solenoid harness connector terminal No. 2. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 12 .
11. Check for harness damage between evaporative emission ventilation solenoid harness connector terminal No. 1 and ECM harness connector C-117 terminal No. 55 (M/T) or PCM harness connector C-120 terminal No. 35 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to next step.
12. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0446 is output, repeat diagnosis. If DTC P0446 is not output, inspection is complete.

Scheme 21

Check conditions are where the throttle valve is closed and vehicle speed is 0.93 mph (1.5 KP/H) or less. Judgement criteria is where if the voltage signal from the fuel tank differential pressure sensor changes by 0.2 volt or more, DTC P0451 will set. The code may also set if a sudden pressure fluctuation occurs twenty times while the engine is idling, and then eight consecutive times during normal driving. The conditions for deviating from idling operation are as follows: Engine speed is greater than 2,500 RPM, vehicle speed is 9.3 mph (15 KP/H) or greater and volumetric efficiency is 55% or greater.

Note. If the number of sudden pressure fluctuations does not reach twenty during any one period of engine idling, or if the ignition switch is turned off, the counter will reset to zero.

The most likely causes for this DTC to be set are

1. Fuel tank differential pressure sensor failed.
2. Damaged harness in fuel tank differential pressure sensor circuit.
3. ECM (M/T) or PCM (A/T) failed.

Required Special Tools is Test Harness Set (MB991658).

1. Connect scan tool to data link connector. Disconnect and plug hose "G" from evaporative emission canister. Turn ignition on. Remove fuel cap. Using scan tool, set scan tool to the data reading mode for data list item 73: FUEL TANK DIFFERENTIAL PRESSURE SENSOR. The fuel tank pressure should be -285 to 285 in. Hg. (-1.5 to 1.5 kPa). Connect an evaporative emission system pressure pump to fuel filler neck, and apply pressure. Scan tool reading should increase. Turn ignition switch to LOCK position. Disconnect scan tool. If scan tool reading is not within the specified value, go to next step. If scan tool reading is within the specified value, go to step 26 .
2. Remove the rear seat cushion. Pull up on carpet. Using a DVOM connected to ground, backprobe 13-pin intermediate harness connector D-14 terminal No. 11. Turn ignition on. Remove fuel cap. Voltage reading should be 2.0-3.0 volts. Using evaporative emission pump, apply pressure to fuel tank. Voltage reading should increase. Turn ignition switch to LOCK position. If voltage readings are as specified, go to next step. If voltage readings are not as specified, go to step 7 .
3. Do not disconnect ECM harness connector C-117 (M/T) or PCM harness connector C-116 (A/T). Turn ignition on. Disconnect and plug hose "G" from evaporative emission canister. Using DVOM connected to ground, backprobe ECM harness connector C-117 terminal No. 61 or PCM harness connector C-116 terminal No. 92. Remove fuel cap. Voltage reading should be 2.0-3.0 volts. Using evaporative emission pump, apply pressure to fuel tank. Voltage reading should increase. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 6 .
4. Check for damage in intermediate harness connectors D-14 and ECM harness connector C-117 (M/T) or PCM harness connector C-116 (A/T). Repair or replace as necessary. After repairs, go to step 26 . If connectors are in good condition, go to next step.
5. Disconnect and plug hose "G" from evaporative emission canister. Turn ignition on. Remove fuel filler cap. Set scan tool to data reading mode for item 73: FUEL TANK DIFFERENTIAL PRESSURE SENSOR. The fuel tank pressure should be -285 to 285 in. Hg. (-1.5 to 1.5 kPa). Connect evaporative emission system pressure pump to fuel filler neck, and apply pressure. The scan tool reading should increase. Turn ignition switch to LOCK position. Disconnect scan tool. If scan tool reading is not within the specified value, replace ECM or PCM. After replacing ECM or PCM, go to step 26 . If the scan tool reading is within the specified value, problem is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
6. Check for open or damage to harness between the fuel tank differential pressure sensor harness connector and ECM harness connector C-117 terminal No. 61 (M/T) or PCM harness connector C-116 terminal No. 92. Repair or replace as necessary. After repairs, go to step 26 . If circuits or connectors are okay, go to step 26 .
7. Turn ignition on. Using DVOM connected to ground, backprobe 13-pin intermediate harness connector D-14 terminal No. 9. Voltage reading should be 4.7-5.1 volts. Turn ignition off. If voltage reading is as specified, go to step 12 . If voltage reading is not as specified, go to next step.
8. Do not disconnect ECM or PCM harness connectors. Turn ignition on. Using DVOM connected to ground, backprobe ECM harness connector C-115 terminal No. 81 (M/T) or PCM harness connector C-118 terminal No. 46 (A/T). Voltage reading should be 4.7-5.1 volts. Turn ignition off. If voltage reading is as specified, go to next step. If voltage reading is not as specified, go to step 10 .
9. Check for open or damage harness between 13-pin intermediate harness connector D-14 terminal No. 9 and ECM harness connector C-115 terminal No. 81 (M/T) or PCM harness connector C-118 terminal No. 46 (A/T). Repair or replace as necessary. After repairs, go to step 26 . If circuits or connectors are okay, go to step 26 .
10. Check for damage in 13-pin intermediate harness connector D-14 and ECM harness connector C-115 (M/T) or PCM harness connector C-118. Repair or replace as necessary. After repairs, go to step 26 . If connectors are okay, go to next step.
11. Check for short to ground in circuit between 13-pin intermediate harness connector D-14 terminal No. 9 and ECM harness connector C-115 terminal No. 81 (M/T) or PCM harness connector C-118 terminal No. 46 (A/T). Repair or replace as necessary. After repairs, go to step 26 . If circuit is okay, go to step 5 .
12. Do not disconnect 13-pin intermediate harness connector D-14. Turn ignition on. Using DVOM connected to ground, backprobe 13-pin intermediate harness connector D-14, terminal No. 10. Voltage reading should be 0.5 volt or less. Turn ignition off. If voltage reading is as specified, go to step 16 . If voltage reading is not as specified, go to next step.
13. Do not disconnect ECM or PCM harness connectors. Turn ignition on. Using DVOM connected to ground, backprobe ECM harness connector C-115 terminal No. 92 (M/T) or PCM harness connector C-118 terminal No. 57 (A/T). Voltage reading should be 0.5 volt or less. If voltage is not as specified, go to step 15 . If voltage reading is as specified, go to next step.
14. Check for open circuit or damage between intermediate harness connector D-14 terminal No. 10 and ECM harness connector C-115 terminal No. 92 (M/T) or PCM harness connector C-118 terminal No. 57 (A/T). Repair or replace as necessary. After repairs, go to step 26 . If no problem is found, go to step 26 .
15. Check for damage in ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T). Repair or replace as necessary. After repairs, go to step 26 . If connector is okay, go to step 5 .
16. Remove fuel tank. Plug fuel filler hose, fuel pump feed nipple, return hose, hose "L" and hose "H" connected to fuel tank. Raise fuel tank closer to closer. Using Special Tool (MB991658), connect between fuel tank differential pressure harness connector and fuel tank differential pressure. Turn ignition on. Connect DVOM between ground and special tool connector terminal No. 1. Observe DVOM. When plug is removed from filler hose, voltage reading should be 2-3 volts. Using a evaporative emission pump, apply pressure to filler hose. Voltage should increase. Turn ignition off. If voltage reading is as specified, go to next step. If voltage reading is not as specified, go to step 19 .
17. Check harness connector at fuel tank differential pressure sensor and intermediate harness connector. Repair or replace as necessary. Reinstall fuel tank. After repairs, go to step 26 . If harness connectors are okay, go to next step.
18. Check harness for short to ground between fuel tank differential pressure sensor harness connector terminal No. 1 and intermediate harness connector D-14 terminal No. 11. Repair as necessary. After repairs, reinstall fuel tank, then go to step 26 . If circuit is okay, reinstall fuel tank, then go to step 26 .
19. Turn ignition on. Check voltage between ground and fuel tank differential pressure sensor terminal No. 3. Voltage reading should be 4.7-5.1 volts. Turn ignition off. If voltage reading is as specified, go to step 22 . If voltage reading is not as specified, go to next step.
20. Check for damage in fuel tank differential pressure sensor harness connector and intermediate connector D-14. Repair or replace as necessary. Reinstall fuel tank. After repairs, go to step 26 . If harness connectors are okay, go to next step.
21. Check for short circuit to ground between fuel tank differential pressure sensor harness connector terminal No. 3 and intermediate connector D-14 terminal No. 9. Repair or replace as necessary. Reinstall fuel tank. After repairs, go to step 26 . If circuit is okay, reinstall fuel tank and go to step 26 .
22. Turn ignition on. Check voltage between ground and fuel tank differential pressure sensor harness connector terminal No. 2. Voltage reading should be 0.5 volt or less. Turn ignition off. If voltage reading is as specified, go to step 25 . If voltage reading is not as specified, go to next step.
23. Check for damage in fuel differential pressure sensor harness connector and intermediate harness connector. Repair as necessary. After repairs, go to step 26 . If connectors are okay, go to next step.
24. Check for short to ground between fuel tank differential pressure sensor harness connector terminal No. 2 and intermediate harness connector terminal No. 10. Repair as necessary. Reinstall fuel tank. After repairs, go to step 26 . If circuit is okay, reinstall fuel tank, then go to step 26 .
25. Check for damage at fuel tank differential pressure sensor harness connector. Repair or replace as necessary. After repairs, go to next step. If connector is okay, replace fuel tank differential sensor. Reinstall fuel tank. After repairs, go to next step.
26. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «EVAP SYSTEM LEAK MONITOR»(ref-152075-S34246869422003011300000) under VERIFYING REPAIRS. Read DTCs. If DTC P0451 is reset, go to step 2 . If DTC P0451 is not reset, diagnosis is complete.

Test conditions are when intake air temperature is more than 41°F (5°C), engine speed is 1600 RPM or more and volumetric efficiency is 20-80 percent. Judgment criteria is when the evaporative emission purge solenoid is off and fuel differential pressure sensor output voltage remains 1.0 volt or less for 10 seconds.

The most likely causes for this DTC to be set are

1. Fuel tank differential pressure sensor failed.
2. Open fuel tank differential pressure sensor circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

Required Special Tools are Scan Tool (MUT-II - (MB991502)) and Test Harness Set (MB991658).

1. Connect scan tool to data link connector. Disconnect and plug hose "G" from evaporative emission canister. Turn ignition on. Remove fuel cap. Using scan tool, set scan tool to the data reading mode for data list item 73: FUEL TANK DIFFERENTIAL PRESSURE SENSOR. The fuel tank pressure should be -285 to 285 in. Hg. (-1.5 to 1.5 kPa). Connect an evaporative emission system pressure pump to fuel filler neck, and apply pressure. Scan tool reading should increase. Turn ignition switch to LOCK position. Disconnect scan tool. If scan tool reading is not within the specified value, go to next step. If scan tool reading is within the specified value, go to step 26 .
2. Remove the rear seat cushion. Pull up on carpet. Using a DVOM connected to ground, backprobe 13-pin intermediate harness connector D-14 terminal No. 11. Turn ignition on. Remove fuel cap. Voltage reading should be 2.0-3.0 volts. Using evaporative emission pump, apply pressure to fuel tank. Voltage reading should increase. Turn ignition switch to LOCK position. If voltage readings are as specified, go to next step. If voltage readings are not as specified, go to step 7 .
3. Do not disconnect ECM harness connector C-117 (M/T) or PCM harness connector C-116 (A/T). Turn ignition on. Disconnect and plug hose "G" from evaporative emission canister. Using DVOM connected to ground, backprobe ECM harness connector C-117 terminal No. 61 or PCM harness connector C-116 terminal No. 92. Remove fuel cap. Voltage reading should be 2.0-3.0 volts. Using evaporative emission pump, apply pressure to fuel tank. Voltage reading should increase. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 6 .
4. Check for damage in intermediate harness connectors D-14 and ECM harness connector C-117 (M/T) or PCM harness connector C-116 (A/T). Repair or replace as necessary. After repairs, go to step 26 . If connectors are in good condition, go to next step.
5. Disconnect and plug hose "G" from evaporative emission canister. Turn ignition on. Remove fuel filler cap. Set scan tool to data reading mode for item 73: FUEL TANK DIFFERENTIAL PRESSURE SENSOR. The fuel tank pressure should be -285 to 285 in. Hg. (-1.5 to 1.5 kPa). Connect evaporative emission system pressure pump to fuel filler neck, and apply pressure. The scan tool reading should increase. Turn ignition switch to LOCK position. Disconnect scan tool. If scan tool reading is not within the specified value, replace ECM or PCM. After replacing ECM or PCM, go to step 26 . If the scan tool reading is within the specified value, problem is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
6. Check for open or damage to harness between the fuel tank differential pressure sensor harness connector and ECM harness connector C-117 terminal No. 61 (M/T) or PCM harness connector C-116 terminal No. 92. Repair or replace as necessary. After repairs, go to step 26 . If circuits or connectors are okay, go to step 26 .
7. Turn ignition on. Using DVOM connected to ground, backprobe 13-pin intermediate harness connector D-14 terminal No. 9. Voltage reading should be 4.7-5.1 volts. Turn ignition off. If voltage reading is as specified, go to step 12 . If voltage reading is not as specified, go to next step.
8. Do not disconnect ECM or PCM harness connectors. Turn ignition on. Using DVOM connected to ground, backprobe ECM harness connector C-115 terminal No. 81 (M/T) or PCM harness connector C-118 terminal No. 46 (A/T). Voltage reading should be 4.7-5.1 volts. Turn ignition off. If voltage reading is as specified, go to next step. If voltage reading is not as specified, go to step 10 .
9. Check for open or damage in harness between 13-pin intermediate harness connector D-14 terminal No. 9 and ECM harness connector C-115 terminal No. 81 (M/T) or PCM harness connector C-118 terminal No. 46 (A/T). Repair or replace as necessary. After repairs, go to step 26 . If circuits or connectors are okay, go to step 26 .
10. Check for damage in 13-pin intermediate harness connector D-14 and ECM harness connector C-115 (M/T) or PCM harness connector C-118. Repair or replace as necessary. After repairs, go to step 26 . If connectors are okay, go to next step.
11. Check for short to ground in circuit between 13-pin intermediate harness connector D-14 terminal No. 9 and ECM harness connector C-115 terminal No. 81 (M/T) or PCM harness connector C-118 terminal No. 46 (A/T). Repair or replace as necessary. After repairs, go to step 26 . If circuit is okay, go to step 5 .
12. Do not disconnect 13-pin intermediate harness connector D-14. Turn ignition on. Using DVOM connected to ground, backprobe 13-pin intermediate harness connector D-14, terminal No. 10. Voltage reading should be 0.5 volt or less. Turn ignition off. If voltage reading is as specified, go to step 16 . If voltage reading is not as specified, go to next step.
13. Do not disconnect ECM or PCM harness connectors. Turn ignition on. Using DVOM connected to ground, backprobe ECM harness connector C-115 terminal No. 92 (M/T) or PCM harness connector C-118 terminal No. 57 (A/T). Voltage reading should be 0.5 volt or less. If voltage is not as specified, go to step 15 . If voltage reading is as specified, go to next step.
14. Check for open circuit or damage between intermediate harness connector D-14 terminal No. 10 and ECM harness connector C-115 terminal No. 92 (M/T) or PCM harness connector C-118 terminal No. 57 (A/T). Repair or replace as necessary. After repairs, go to step 26 . If no problem is found, go to step 26 .
15. Check for damage in ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T). Repair or replace as necessary. After repairs, go to step 26 . If connector is okay, go to step 5 .
16. Remove fuel tank. Plug fuel filler hose, fuel pump feed nipple, return hose, hose "L" and hose "H" connected to fuel tank. Raise fuel tank closer to closer. Using Special Tool (MB991658), connect between fuel tank differential pressure harness connector and fuel tank differential pressure. Turn ignition on. Connect DVOM between ground and special tool connector terminal No. 1. Observe DVOM. When plug is removed from filler hose, voltage reading should be 2-3 volts. Using a evaporative emission pump, apply pressure to filler hose. Voltage should increase. Turn ignition off. If voltage reading is as specified, go to next step. If voltage reading is not as specified, go to step 19 .
17. Check harness connector at fuel tank differential pressure sensor and intermediate harness connector. Repair or replace as necessary. Reinstall fuel tank. After repairs, go to step 26 . If harness connectors are okay, go to next step.
18. Check harness for short to ground between fuel tank differential pressure sensor harness connector terminal No. 1 and intermediate harness connector D-14 terminal No. 11. Repair as necessary. After repairs, reinstall fuel tank, then go to step 26 . If circuit is okay, reinstall fuel tank, then go to step 26 .
19. Turn ignition on. Check voltage between ground and fuel tank differential pressure sensor terminal No. 3. Voltage reading should be 4.7-5.1 volts. Turn ignition off. If voltage reading is as specified, go to step 22 . If voltage reading is not as specified, go to next step.
20. Check for damage in fuel tank differential pressure sensor harness connector and intermediate connector D-14. Repair or replace as necessary. Reinstall fuel tank. After repairs, go to step 26 . If harness connectors are okay, go to next step.
21. Check for short circuit to ground between fuel tank differential pressure sensor harness connector terminal No. 3 and intermediate connector D-14 terminal No. 9. Repair or replace as necessary. Reinstall fuel tank. After repairs, go to step 26 . If circuit is okay, reinstall fuel tank and go to step 26 .
22. Turn ignition on. Check voltage between ground and fuel tank differential pressure sensor harness connector terminal No. 2. Voltage reading should be 0.5 volt or less. Turn ignition off. If voltage reading is as specified, go to step 25 . If voltage reading is not as specified, go to next step.
23. Check for damage in fuel differential pressure sensor harness connector and intermediate harness connector. Repair as necessary. After repairs, go to step 26 . If connectors are okay, go to next step.
24. Check for short to ground between fuel tank differential pressure sensor harness connector terminal No. 2 and intermediate harness connector terminal No. 10. Repair as necessary. Reinstall fuel tank. After repairs, go to step 26 . If circuit is okay, reinstall fuel tank, then go to step 26 .
25. Check for damage at fuel tank differential pressure sensor harness connector. Repair or replace as necessary. After repairs, go to next step. If connector is okay, replace fuel tank differential sensor. Reinstall fuel tank. After repairs, go to next step.
26. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «EVAP SYSTEM LEAK MONITOR»(ref-152075-S34246869422003011300000) under VERIFYING REPAIRS. Read DTCs. If DTC P0451 is reset, go to step 2 . If DTC P0451 is not reset, diagnosis is complete.

Test conditions are when intake air temperature is 41-113°F (5-45°C) or more, engine speed is 1600 RPM or more and volumetric efficiency is 20-80 percent. Judgment criteria is when the evaporative emission purge solenoid valve is activating at 100 percent ratio and the fuel differential pressure sensor output voltage remains 4.0 volts or more for ten seconds.

The most likely causes for this DTC to be set are

1. Fuel tank differential pressure sensor failed.
2. Open fuel tank differential pressure sensor circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

Required Special Tools are Scan Tool (MUT-II - (MB991502)) and Test Harness Set (MB991658).

1. Connect scan tool to data link connector. Disconnect and plug hose "G" from evaporative emission canister. Turn ignition on. Remove fuel cap. Using scan tool, set scan tool to the data reading mode for data list item 73: FUEL TANK DIFFERENTIAL PRESSURE SENSOR. The fuel tank pressure should be -285 to 285 in. Hg. (-1.5 to 1.5 kPa). Connect an evaporative emission system pressure pump to fuel filler neck, and apply pressure. Scan tool reading should increase. Turn ignition switch to LOCK position. Disconnect scan tool. If scan tool reading is not within the specified value, go to next step. If scan tool reading is within the specified value, go to step 26 .
2. Remove the rear seat cushion. Pull up on carpet. Using a DVOM connected to ground, backprobe 13-pin intermediate harness connector D-14 terminal No. 11. Turn ignition on. Remove fuel cap. Voltage reading should be 2.0-3.0 volts. Using evaporative emission pump, apply pressure to fuel tank. Voltage reading should increase. Turn ignition switch to LOCK position. If voltage readings are as specified, go to next step. If voltage readings are not as specified, go to step 7 .
3. Do not disconnect ECM harness connector C-117 (M/T) or PCM harness connector C-116 (A/T). Turn ignition on. Disconnect and plug hose "G" from evaporative emission canister. Using DVOM connected to ground, backprobe ECM harness connector C-117 terminal No. 61 or PCM harness connector C-116 terminal No. 92. Remove fuel cap. Voltage reading should be 2.0-3.0 volts. Using evaporative emission pump, apply pressure to fuel tank. Voltage reading should increase. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 6 .
4. Check for damage in intermediate harness connectors D-14 and ECM harness connector C-117 (M/T) or PCM harness connector C-116 (A/T). Repair or replace as necessary. After repairs, go to step 26 . If connectors are in good condition, go to next step.
5. Disconnect and plug hose "G" from evaporative emission canister. Turn ignition on. Remove fuel filler cap. Set scan tool to data reading mode for item 73: FUEL TANK DIFFERENTIAL PRESSURE SENSOR. The fuel tank pressure should be -285 to 285 in. Hg. (-1.5 to 1.5 kPa). Connect evaporative emission system pressure pump to fuel filler neck, and apply pressure. The scan tool reading should increase. Turn ignition switch to LOCK position. Disconnect scan tool. If scan tool reading is not within the specified value, replace ECM or PCM. After replacing ECM or PCM, go to step 26 . If the scan tool reading is within the specified value, problem is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
6. Check for open or damage to harness between the fuel tank differential pressure sensor harness connector and ECM harness connector C-117 terminal No. 61 (M/T) or PCM harness connector C-116 terminal No. 92. Repair or replace as necessary. After repairs, go to step 26 . If circuits or connectors are okay, go to step 26 .
7. Turn ignition on. Using DVOM connected to ground, backprobe 13-pin intermediate harness connector D-14 terminal No. 9. Voltage reading should be 4.7-5.1 volts. Turn ignition off. If voltage reading is as specified, go to step 12 . If voltage reading is not as specified, go to next step.
8. Do not disconnect ECM or PCM harness connectors. Turn ignition on. Using DVOM connected to ground, backprobe ECM harness connector C-115 terminal No. 81 (M/T) or PCM harness connector C-118 terminal No. 46 (A/T). Voltage reading should be 4.7-5.1 volts. Turn ignition off. If voltage reading is as specified, go to next step. If voltage reading is not as specified, go to step 10 .
9. Check for open or damage harness between 13-pin intermediate harness connector D-14 terminal No. 9 and ECM harness connector C-115 terminal No. 81 (M/T) or PCM harness connector C-118 terminal No. 46 (A/T). Repair or replace as necessary. After repairs, go to step 26 . If circuits or connectors are okay, go to step 26 .
10. Check for damage in 13-pin intermediate harness connector D-14 and ECM harness connector C-115 (M/T) or PCM harness connector C-118. Repair or replace as necessary. After repairs, go to step 26 . If connectors are okay, go to next step.
11. Check for short to ground in circuit between 13-pin intermediate harness connector D-14 terminal No. 9 and ECM harness connector C-115 terminal No. 81 (M/T) or PCM harness connector C-118 terminal No. 46 (A/T). Repair or replace as necessary. After repairs, go to step 26 . If circuit is okay, go to step 5 .
12. Do not disconnect 13-pin intermediate harness connector D-14. Turn ignition on. Using DVOM connected to ground, backprobe 13-pin intermediate harness connector D-14, terminal No. 10. Voltage reading should be 0.5 volt or less. Turn ignition off. If voltage reading is as specified, go to step 16 . If voltage reading is not as specified, go to next step.
13. Do not disconnect ECM or PCM harness connectors. Turn ignition on. Using DVOM connected to ground, backprobe ECM harness connector C-115 terminal No. 92 (M/T) or PCM harness connector C-118 terminal No. 57 (A/T). Voltage reading should be 0.5 volt or less. If voltage is not as specified, go to step 15 . If voltage reading is as specified, go to next step.
14. Check for open circuit or damage between intermediate harness connector D-14 terminal No. 10 and ECM harness connector C-115 terminal No. 92 (M/T) or PCM harness connector C-118 terminal No. 57 (A/T). Repair or replace as necessary. After repairs, go to step 26 . If no problem is found, go to step 26 .
15. Check for damage in ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T). Repair or replace as necessary. After repairs, go to step 26 . If connector is okay, go to step 5 .
16. Remove fuel tank. Plug fuel filler hose, fuel pump feed nipple, return hose, hose "L" and hose "H" connected to fuel tank. Raise fuel tank closer to closer. Using Special Tool (MB991658), connect between fuel tank differential pressure harness connector and fuel tank differential pressure. Turn ignition on. Connect DVOM between ground and special tool connector terminal No. 1. Observe DVOM. When plug is removed from filler hose, voltage reading should be 2-3 volts. Using a evaporative emission pump, apply pressure to filler hose. Voltage should increase. Turn ignition off. If voltage reading is as specified, go to next step. If voltage reading is not as specified, go to step 19 .
17. Check harness connector at fuel tank differential pressure sensor and intermediate harness connector. Repair or replace as necessary. Reinstall fuel tank. After repairs, go to step 26 . If harness connectors are okay, go to next step.
18. Check harness for short to ground between fuel tank differential pressure sensor harness connector terminal No. 1 and intermediate harness connector D-14 terminal No. 11. Repair as necessary. After repairs, reinstall fuel tank, then go to step 26 . If circuit is okay, reinstall fuel tank, then go to step 26 .
19. Turn ignition on. Check voltage between ground and fuel tank differential pressure sensor terminal No. 3. Voltage reading should be 4.7-5.1 volts. Turn ignition off. If voltage reading is as specified, go to step 22 . If voltage reading is not as specified, go to next step.
20. Check for damage in fuel tank differential pressure sensor harness connector and intermediate connector D-14. Repair or replace as necessary. Reinstall fuel tank. After repairs, go to step 26 . If harness connectors are okay, go to next step.
21. Check for short circuit to ground between fuel tank differential pressure sensor harness connector terminal No. 3 and intermediate connector D-14 terminal No. 9. Repair or replace as necessary. Reinstall fuel tank. After repairs, go to step 26 . If circuit is okay, reinstall fuel tank and go to step 26 .
22. Turn ignition on. Check voltage between ground and fuel tank differential pressure sensor harness connector terminal No. 2. Voltage reading should be 0.5 volt or less. Turn ignition off. If voltage reading is as specified, go to step 25 . If voltage reading is not as specified, go to next step.
23. Check for damage in fuel differential pressure sensor harness connector and intermediate harness connector. Repair as necessary. After repairs, go to step 26 . If connectors are okay, go to next step.
24. Check for short to ground between fuel tank differential pressure sensor harness connector terminal No. 2 and intermediate harness connector terminal No. 10. Repair as necessary. Reinstall fuel tank. After repairs, go to step 26 . If circuit is okay, reinstall fuel tank, then go to step 26 .
25. Check for damage at fuel tank differential pressure sensor harness connector. Repair or replace as necessary. After repairs, go to next step. If connector is okay, replace fuel tank differential sensor. Reinstall fuel tank. After repairs, go to next step.
26. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «EVAP SYSTEM LEAK MONITOR»(ref-152075-S34246869422003011300000) under VERIFYING REPAIRS. Read DTCs. If DTC P0451 is reset, go to step 2 . If DTC P0451 is not reset, diagnosis is complete.

Test Conditions A: At start-up, intake air temperature is 97°F (36°C) or less when engine is started. The engine coolant temperature 97°F (36°C) or less when engine is started.

Test Conditions B: For test to run, engine coolant temperature is 140°F (60°C) or more with fuel level of 15-40 percent or engine coolant temperature 68°F (20°C) or more with fuel level of 40-85 percent, engine speed is 1600 RPM or more, barometric pressure is above 11 psi (76 kPa), volumetric efficiency is 20-70 percent, fuel temperature is 97°F (36°C) or less, and fuel tank differential pressure sensor output voltage 1-4 volts.

Test Conditions C: For test to stop, intake air temperature is greater than 41°F (5°C), when the evaporative emission purge solenoid and evaporative emission ventilation solenoid are closed, the pressure in the fuel tank rises to 0.065 psi (451 Pa) or less and the amount of remaining fuel is 15-40 percent of capacity upon engine start up. When the evaporative emission purge solenoid and evaporative emission ventilation solenoid are closed, the pressure in the fuel tank rises to 0.047 psi (324 Pa) or less and the amount of remaining fuel is 40-85 percent of capacity upon engine start up. 10 seconds have elapsed from the start of the previous monitoring and monitoring time: 130 seconds.

Judgement criteria is when the fuel tank internal pressure is greater than 0.29 psi (2 kPa) after the evaporative emission purge solenoid has been driven when the fuel tank and vapor line were closed.

The most likely causes for this DTC to be set are

1. Loose fuel cap.
2. Fuel cap relief pressure is incorrect.
3. Fuel overflow limiter valve failed.
4. Purge line or vapor line is clogged.
5. Fuel tank, purge line or vapor line seal failed.
6. Evaporative emission purge solenoid failed.
7. Evaporative emission ventilation solenoid failed.
8. Fuel tank differential pressure sensor failed.
9. Evaporative emission canister seal is faulty.
10. Evaporative emission canister is clogged.

Note. In this mode, the ECM or PCM will automatically increase engine speed to 1600 RPM or more. Ensure transaxle is in Park (A/T) or Neutral (M/T).

1. Connect scan tool to data link connector. Turn ignition on. Erase/clear DTCs using scan tool. Check that fuel cap is securely closed. (Tighten until 3 clicks are heard.) Start engine. Select System Test, and press the YES key. Select EVAP LEAK MON, and press the YES key. During the monitor, keep accelerator pedal at idling position. Keep engine speed and engine load within the specified range. When monitor test starts, the IN PROGRESS item on scan tool will change from NO to YES. If EVAP LEAK MON. COMPLETED. TEST PASSED is displayed, evaporative emission system is working properly at this time. Explain to customer that improperly tightened fuel cap can cause MIL to turn on. Return vehicle to customer. If EVAP LEAK MON. COMPLETED. TEST FAILED AND DTCS SET is displayed, a malfunction has been detected during the monitor test. Go to next step. If EVAP LEAD MON. DISCONTINUED. RETEST AGAIN FROM THE FIRST is displayed, monitor was discontinued for a certain reason (vehicle speed input from computer, engine speed and engine load deviating from specified range). Turn ignition switch to LOCK position once, and repeat the monitoring test.
2. Using scan tool, check solenoid for clogging of purge control. Disconnect hoses "A" and "B" from the evaporative emission purge solenoid. Connect a hand-held vacuum pump to the evaporative emission purge solenoid instead of hose "B". Turn ignition on. Set scan tool to actuator test mode item 08: EVAPORATIVE EMISSION PURGE SOLENOID. When evaporative emission purge solenoid is operated, apply a pressure on the vacuum pump and confirm that air is blown from the other side nipple. Turn ignition switch to LOCK position. Disconnect scan tool. Disconnect vacuum pump, and connect hoses "A" and "B" to evaporative emission purge solenoid. If solenoid is in good condition, go to next step. If solenoid is not in good condition, replace evaporative emission purge solenoid. After replacing solenoid, go to step 20.
3. Check for leaks and clogging in the evaporator line hose "A" to hose "C". Repair or replace as necessary. After repairs, go to step 20. If hoses are in good condition, go to next step.
4. Check for leaks and clogging in the chamber. When you blow the chamber, it should pass less air. When you blow the chamber, on air should leak from the chamber body. If the chamber is in good condition, go to next step. If the chamber is not in good condition, replace the chamber. Then go to step 20.
5. Check the evaporative emission ventilation solenoid using scan tool. Connect scan tool to data link connector. Disconnect hose "F" from the evaporative emission ventilation solenoid side and connect a hand-held vacuum pump to hose. Turn ignition on. Set scan tool to actuator test mode for item actuator test item 29: EVAPORATIVE EMISSION VENTILATION SOLENOID. When evaporative emission ventilation solenoid is operated, apply a pressure on the vacuum pump and confirm that pressure is maintained. Turn ignition switch to LOCK position. Disconnect scan tool. Disconnect vacuum pump and connect hose "F" to evaporative emission canister. If solenoid valve and hose is in good condition, go to next step. If solenoid valve and hose is not in good condition, go to next step.
6. Check for leaks and clogging in evaporator line hose "D" and "E". Replace as necessary. After replacing hose(s), go to step 20. If hose(s) are okay, go to next step.
7. Check for leaks in the evaporator line from hose "G" to hose "P". Disconnect and plug hose "G" from evaporative emission canister (located under left rear of vehicle). Remove fuel filler cap. Connect evaporative emission system pressure pump to fuel filler neck. Using pump, apply pressure. Observe if pressure is maintained. If pressure is maintained, go to step 14. If pressure is not maintained, go to next step.
8. Check for leaks in evaporator line hoses "G", "I", "J" and "K". Remove filler neck protector. Perform leakage test with a hand-held vacuum pump on each hose from hoses "G", "I", "J" and "K". Replace as necessary. After replacing hose(s), reinstall filler neck protector, then go to step 20. If hoses are in good condition, go to next step.
9. Inspect check valve "A" (valve is located between hoses "I" and "J"). Check valve should pass air only from the direction shown. (Scheme 21) Replace as necessary. After replacing check valve, go to step 20. If check valve is okay, go to next step.
10. Remove fuel tank. Check for leaks in evaporator line hoses "H", "L", "M", "N", "O" and "P". Replace as necessary. After repairs, reinstall fuel tank. If hoses are okay, go to next step.
11. Inspect check valve "B". When you blow through the check valve (Step 1), it should pass more air. When you blow through the check valve in the other direction (Step 2), it should pass less air. No air should leak from the check valve body. If check valve "B" is in good condition, go to next step. If check valve "B" is not in good condition, replace check valve "B"and reinstall fuel tank. After repairs, go to step 20.
12. Check for leaks in fuel tank. Visually check for cracks and leaks, etc. Carefully check the fuel pump assembly and the inner pressure sensor installation in the fuel tank. Connect an evaporative emission system pressure pump to fuel filler hose. Plug fuel pump feed nipple, return hose, and hoses "H" and "L" connected to fuel tank. Apply pressure using the evaporative emission system pressure pump. In the pressurized state, check for leaks by applying soapy water to each section. If there are leaks at the fuel pump assembly, fuel tank differential pressure sensor or rollover valve, reassemble the leaking parts. After reassembling the leaking parts, check again for leaks. After repairs, reinstall fuel tank. After reinstalling fuel tank, go to step 20. If there are leaks at the fuel tank, replace fuel tank. Reinstall fuel tank. After replacing fuel tank, go to step 20. If there are no leaks found, go to next step.
13. Ensure fuel filler cap is securely closed. Tighten until 3 clicks are heard. Ensure transaxle is in Park (A/T) or Neutral (M/T). Start and operate engine at idle. Using scan tool, select EVAP LEAK MON. Keep accelerator pedal at idle position. Idle speed will automatically increase to 1600 RPM or more at this point. Observe scan tool. If scan tool displays EVAP LEAK MON. COMPLETED. TEST PASSED, the evaporative emission system is operating properly. If scan tool displays, EVAP LEAK MON. COMPLETED. TEST FAILED AND DTCS SET, replace ECM (M/T) or PCM (A/T). After replacing ECM or PCM, go to step 20. If scan tool displays EVAP LEAD MON. DISCONTINUED. RETEST AGAIN FROM THE FIRST, the monitor was disconnected for a certain reason (vehicle speed input from ECM or PCM, engine speed and engine load deviating from specified range). Turn ignition off once and recheck evaporative emission system monitor test.
14. Pressure test for clogging in the evaporator line from hose "G" to hose "P". Disconnect and plug hose "G" from the evaporative emission canister side. Remove fuel cap. Using evaporative emission system pressure pump to fuel filler neck and apply pressure. After pressure is maintained, unplug hose "G". If air is blown from hose "G", go to step 20. If air is not blown from hose "G", go to next step.
15. Pressure test for clogging in the evaporator line hoses "G", "I", "J" and "K". Replace as necessary. After replacing hose(s), go to step 20. If hoses are okay, go to next step.
16. Inspect check valve "A". Check valve should pass air only from the direction shown. (Scheme 21) If check valve "A" is in good condition, go to next step. If check valve "A" is not in good condition, replace check valve "A", and reinstall the filler neck assembly. After replacing check valve, go to step 20.
17. Remove fuel tank. Check for clogging in the evaporator line from hoses "H", "L", "M", "N", "O" and "P". Replace as necessary. Reinstall fuel tank. After repairs, go to step 20. If hoses are okay, go to next step.
18. Inspect check valve "B". When you blow through the check valve (Step 1), it should pass more air. When you blow through the check valve in the other direction (Step 2), it should pass less air. No air should leak from the check valve body. If check valve "B" is in good condition, go to next step. If check valve "B" is not in good condition, replace check valve "B"and reinstall fuel tank. After repairs, go to step 20.
19. Disconnect evaporative emission canister hoses "E", "F" and "G". Connect a hand-held vacuum pump to canister nipple "E" and plug the other nipples. Apply pressure using vacuum pump. Confirm is pressure is maintained. Check pressure on remaining canister nipples and plug nipples not tested. If pressure is not maintained, replace evaporative emission canister and fuel tank pressure relief valve. If pressure is maintained, go to step.
20. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «EVAP SYSTEM LEAK MONITOR»(ref-152075-S34246869422003011300000) under VERIFYING REPAIRS. Read DTCs. If DTC P0455 is reset, go to step 1. If DTC P0455 is not reset, diagnosis is complete.

Test Conditions A: At start-up, the fuel level sensor output voltage is 2.4-3.7 volts when the engine starts (i.e., the amount of remaining fuel is 40-85 percent), intake air temperature is 97°F (36°C) or less and engine coolant temperature is 97°F (36°C) or less.

Test Conditions B: For test to run, barometric pressure is greater than 11 psi (76 kPa), fuel temperature is 91°F (33°C) or less, and fuel tank differential pressure sensor output voltage is 1-4 volts.

Test Conditions C: For test to stop, engine coolant temperature is greater than 68°F (20°C) and intake air temperature is greater than 14°F (-10°C). When evaporative emission purge solenoid and evaporative emission ventilation solenoid are closed, the pressure rise in the fuel tank is less than 0.047 psi (324 Pa). 10 seconds have elapsed since the start of the previous monitoring and monitoring time: 10-14 minutes.

Judgment criteria is when internal pressure of the fuel tank fluctuates 0.177-0.199 psi (1177-1373 Pa) or more in 128 seconds after the tank and vapor line were closed. ECM (M/T) or PCM (A/T) monitors for this condition once per drive cycle.

The most likely causes for this DTC to be set are

1. Loose fuel cap.
2. Fuel cap relief pressure is incorrect.
3. Evaporative emission canister seal is faulty.
4. Fuel tank, purge line or vapor line seal failed.
5. Evaporative emission ventilation solenoid valve failed.

Note. If engine speed does not reach 2000 RPM during the monitor test, adjustment of the speed adjusting screw may be needed. Adjust to standard value.

1. Using scan tool, check evaporative emission system monitor test. With this monitor, the ECM (M/T) or PCM (A/T) automatically increases engine speed to 1600 RPM or more. Ensure transaxle is in Park (A/T) or Neutral (M/T). Connect scan tool to data link connector. Turn ignition on. Erase/clear DTCs using scan tool. Ensure fuel cap is securely closed. Tighten until 3 clicks are heard. Start and operate engine at idle. Using scan tool, select SYSTEM TEST and press the YES key. Select EVAP LEAK MON, and press the YES key. During the monitor, keep the accelerator pedal at the idling position. Keep engine speed and engine load within the specified range. When monitor test starts, the in progress item on scan tool will change from NO to YES. Turn ignition switch to LOCK position, and disconnect scan tool. If scan tool displays EVAP LEAK MON. COMPLETED TEST PASSED, evaporative emission system is working properly at this time. Explain to customer that improperly tightened fuel cap can cause MIL to turn on. Return vehicle to customer. If scan tool displays, EVAP LEAK MON. COMPLETE, TEST FAILED AND DTCS SET, a malfunction has been detected during the monitor test. Go to next step. If scan tool displays, EVAP LEAD MON. DISCONTINUED. RETEST AGAIN FROM THE FIRST, the monitor is discontinued for a certain reason (vehicle speed input from computer, engine speed and engine load deviating from specified range). Turn ignition switch to LOCK position once, and repeat the monitoring test.
2. Disconnect hose "C" from evaporative emission purge solenoid. Solenoid is located on top center of engine. Connect a hand-held vacuum pump evaporative emission purge solenoid. Apply vacuum using vacuum pump and confirm that vacuum is maintained. Disconnect vacuum pump and reconnect hose "C" to evaporative emission purge solenoid. If evaporative emission purge solenoid is in good condition, go to next step. If evaporative emission purge solenoid is not in good condition, replace evaporative emission purge solenoid. After replacing solenoid, go to step 15.
3. Check for leaks in evaporator line hose "A" to hose "C". Replace as necessary. After repairs, go to step 15. If hose is okay, go to next step.
4. Connect scan tool to data link connector. Disconnect hose "F" from evaporative emission canister side. Connect hand-held vacuum pump to hose "F". Turn ignition on. Set scan tool to actuator test mode for item actuator test item 29: EVAPORATIVE EMISSION VENTILATION SOLENOID VALVE. When evaporative emission ventilation solenoid is operated, apply a pressure on vacuum pump and confirm that pressure is maintained. Turn ignition switch to LOCK position, and disconnect scan tool. Disconnect vacuum pump and reconnect hose "F" to evaporative emission canister. If solenoid valve is in good condition, go to step 6. If solenoid valve is not in good condition, go to next step.
5. Check for leaks in evaporator line hose "F". Replace as necessary. After replacing hose, go to step 15. If hose is okay, replace evaporative emission ventilation solenoid valve. After replacing solenoid valve, go to step 15.
6. Check for leaks in evaporator line hose "D" to hose "E". Replace as necessary. After repairs, go to step 15. If hose is okay, go to next step.
7. Disconnect and plug hose "G" from evaporative emission canister (located under left rear of vehicle). Remove fuel filler cap. Connect evaporative emission system pressure pump to fuel filler neck. Using pressure pump, apply pressure on evaporative emission system. Confirm that pressure is maintained. If pressure is maintained, go to step 14. If pressure is not maintained, go to next step.
8. Check for leaks in the evaporator line hoses "G", "I", J" and "K". Remove fuel filler neck protector. Perform leakage test using a hand-held vacuum pump on each hose from hoses "G", "I", "K", "J" and "K". Replace as necessary. After replacing hose(s), go to step 15. If hose(s) are okay, go to next step.
9. Inspect check valve "A". Check valve should pass air only from the direction shown. (Scheme 21) If check valve "A" is in good condition, go to next step. If check valve "A" is not in good condition, replace check valve "A", reinstall fuel filler neck protector. After repairs, go to step 15.
10. Remove fuel tank. Check for leaks in evaporator line from hoses "H", "L", "M", "N", "O" and "P". Replace as necessary. Reinstall fuel tank. After repairs, go to step 15. If hoses are okay, go to next step.
11. Inspect check valve "B". When you blow through the check valve (Step 1), it should pass more air. When you blow through the check valve in the other direction (Step 2), it should pass less air. No air should leak from the check valve body. If check valve "B" is in good condition, go to next step. If check valve "B" is not in good condition, replace check valve "B" and reinstall fuel tank. After repairs, go to step 15.
12. Visually check fuel tank for cracks and leaks, etc. Carefully check fuel pump assembly and inner pressure sensor installation in fuel tank. Connect an evaporative emission system pressure pump to fuel filler hose. Plug the filler hose, feed pipe, return pipe and rollover valve nipple connected to fuel tank. Apply pressure using evaporative emission system pressure pump. In the pressurized state, check for leaks by applying soapy water to each section. If leak is found at fuel pump assembly, fuel tank differential pressure sensor, leveling valve or rollover valve, reassembly leaky parts and recheck for leaks. If no leaks are found, reinstall fuel tank, then go to step 15. If leaks are found in fuel tank, replace fuel tank. After replacing fuel tank, go to step 15. If no leaks are found, go to next step..
13. Using scan tool, check evaporative emission system monitor test. Ensure that transaxle is on Park (A/T) or Neutral (M/T). Turn ignition on. Erase/clear DTCs using scan tool. Ensure fuel cap is securely closed. Tighten until 3 clicks are heard. Start engine. Select SYSTEM TEST and press the YES key. Select EVAP LEAK MON, and press the YES key. During the monitor, keep the accelerator pedal at idling position. When monitor test starts, the in-progress item on scan tool will change from NO to YES. Turn ignition switch to LOCK position. Disconnect scan tool. If scan tool displays EVAP LEAK MON. COMPLETED. TEST PASSED, evaporative emission system is working properly at this time. Go to next step. If scan toll displays EVAP LEAK MON. COMPLETED. TEST FAILED AND DTCS SET, replace ECM (M/T) or PCM (A/T). After replacing ECM or PCM, go to next step. If scan tool displays EVAP LEAD MON. DISCONTINUED. RETEST AGAIN FROM THE FIRST, the monitor is discontinued for a certain reason (vehicle speed input from computer, engine speed and engine load deviating from specified range). Turn ignition switch to LOCK position once, and repeat the monitoring test.
14. Disconnect hoses "E", "F" and "G" from evaporative emission canister. Connect hand-held vacuum pump to evaporative emission canister nipple "E". Plug all other nipples. Using vacuum pump, apply pressure to canister. Observe if pressure is maintained. If pressure is maintained, go to step 13. If pressure is not maintained, replace evaporative emission canister and fuel tank pressure relief valve. After repairs, go to next step.
15. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «EVAP SYSTEM LEAK MONITOR»(ref-152075-S34246869422003011300000) under VERIFYING REPAIRS. Read DTCs. If DTC P0456 is reset, go to step 1. If DTC P0456 is not reset, diagnosis is complete.

Scheme 22

Check conditions and judgement criteria are when the fuel consumption calculated from the operation time of the injector amounts to 20 liters, but the change in amount of fuel in tank calculated from the fuel level sensor is 2 liters or less.

The most likely causes for this DTC to be set are

1. Fuel gauge unit failed.
2. Open or shorted fuel gauge unit circuit or loose connector.
3. ECM (M/T) or PCM failed (A/T).

1. Using scan tool, check fuel level sensor. Connect scan tool to data link connector. Turn ignition on. Set scan tool to the data reading mode for data list item 4B: FUEL LEVEL SENSOR. When fuel gauge is near FULL, voltage should be 100-3600 millivolts. When fuel gauge is near EMPTY, voltage should be 2700-6200 millivolts. Turn ignition switch to LOCK position. If the sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) . If sensor is not operating properly, go to next step.
2. Check fuel gauge unit harness connector for damage. Repair or replace as necessary. After repairs, go to step 12 . If connector is in good condition, go to next step.
3. Disconnect fuel gauge harness connector. Using a DVOM, check continuity between fuel gauge harness connector terminal No. 2 and ground. Resistance should be less than 2 ohms. If resistance is as specified, go to next step. If resistance is not as specified, repair open or damage in wiring harness between fuel gauge unit harness connector terminal No. 2 and ground. After repairs, go to step 12 .
4. Turn ignition on. Measure voltage between fuel gauge harness connector terminal No. 1 and ground. Battery voltage should present. Turn ignition switch to LOCK position. If voltage is as specified, go to step 9 . If voltage is not as specified, go to next step.
5. Do not disconnect ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T). Disconnect the combination meter harness connector C-02. Turn ignition on. Measure voltage between ECM harness connector terminal No. 74 (M/T) or PCM harness connector terminal No. 60 (A/T) and ground by backprobing. When fuel gauge is near FULL, voltage should be 0.1 and 3.6 volts. When fuel gauge is near EMPTY, voltage should be 2.7 and 6.2 volts. Turn ignition switch to LOCK position. If voltage is as specified, go to next step. If voltage is not as specified, go to step 7 .
6. Check ECM harness connector C-115 at ECM (M/T) or PCM harness connector C-118 at PCM (A/T) for damage. Repair or replace as necessary. After repairs, go to step 12 . If connector is in good condition, check intermediate harness connectors C-124, C-127 and D-14 for damage. Repair or replace as necessary. After repairs, go to step 12 . If intermediate harness connectors are okay, repair open in wiring harness between fuel gauge unit harness connector terminal No. 1 and ECM harness connector C-115 terminal No. 74 (M/T) or PCM harness connector C-118 terminal No. 60 (A/T). After repairs, go to step 12 .
7. Check for damage in ECM harness connector C-115 (M/T) or PCM harness connector C-118. Repair or replace as necessary. After repairs, go to step 12 . If connector is okay, go to next step.
8. Check for short circuit to ground between fuel gauge unit harness connector terminal No. 1 and ECM harness connector C-115 terminal No. 74 (M/T) or PCM harness connector C-118 terminal No. 60 (A/T). Repair as necessary. After repairs, go to step 12 . If wiring harness is in good condition, replace ECM (M/T) or PCM (A/T). After replacing ECM or PCM, go to step 12 .
9. Check fuel gauge unit. Replace as necessary. After replacing fuel gauge, go to 12 . If fuel gauge unit is okay, go to next step.
10. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 12 . If connector is in good condition, go to next step.
11. Check for harness damage between fuel gauge unit harness connector terminal No. 1 and ECM harness connector C-115 terminal No. 74 (M/T) or PCM harness connector C-118 terminal No. 60 (A/T). If wiring harness is in good condition, replace ECM (M/T) or PCM (A/T). After replacing ECM or PCM, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to next step.
12. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0460 is output, repeat diagnosis. If DTC P0460 is not output, inspection is complete.

Scheme 23

Check conditions are when 2 seconds or more have passed the starting sequence was completed, engine speed is 2000-4000 RPM and volumetric efficiency is 48-100 percent. Judgement criteria is when vehicle speed sensor output voltage has not changed (no pulse signal is input) for 2 seconds.

The most likely causes for this DTC to be set are

1. Vehicle speed sensor failed.
2. Open or shorted vehicle speed sensor circuit or loose connector.
3. ECM failed.

Scheme 24

1. Connect scan tool to data link connector. Start engine. Set scan tool to the data reading mode for data list item 24: VEHICLE SPEED SENSOR. Drive vehicle to about 25 MPH (40 KP/H). Check that speedometer and (MUT-II) display speed matches. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000). If the sensor is not operating properly, go to next step.
2. Check speedometer. If speedometer is functioning, go to next step. If speedometer is not functioning, go to step 8.
3. Using an oscilloscope, check the sensor output voltage at ECM harness connector C-115. Do not disconnect ECM harness connector C-115. Disconnect the combination meter harness connector and auto-cruise control ECU harness connector and A/C-ECU harness connector. Connect oscilloscope probe to ECM terminal No. 86 by backprobing. Start engine. Check the waveform. The waveform should be a normal pattern. (Scheme 27) Turn ignition switch to LOCK position. If waveform is as specified, go to next step. If waveform is not as specified, go to step 6.
4. Check ECM harness connector C-115 for damage. Repair or replace as necessary. After repairs, go to step 17. If connector is in good condition, go to next step.
5. Using scan tool, check vehicle speed sensor. Connect scan tool to data link connector. Start engine. Set scan tool to the data reading mode for data list item 24: VEHICLE SPEED SENSOR. Check that the speedometer and (MUT-II) display speed match when traveling at a vehicle speed of 25 MPH (40 KP/H). If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000). If sensor is not operating properly, replace ECM. After replacing ECM, go to step 17.
6. Do not disconnect the ECM harness connector C-115. Disconnect vehicle speed sensor harness connector. Vehicle speed sensor is located on top of transaxle. Turn ignition on. Using a DVOM, check voltage between ECM harness connector C-115 terminal No. 86 and ground. Voltage reading should be 4.8-5.2 volts. If voltage is as specified, go to next step. If voltage is not as specified, replace ECM. After replacing ECM, go to step 17.
7. Check for damage in ECM harness connector C-115. If connector in good condition, check intermediate connector C-124 for damage and repair or replace as required. If intermediate connector is in good condition, repair open in wiring harness between vehicle speed sensor harness connector terminal No. 3 and ECM harness connector C-115 terminal No. 86. After repairs, go to step 17. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 17.
8. Check vehicle speed sensor harness connector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 17.
9. Turn ignition on. Measure voltage between vehicle speed sensor harness connector terminal No. 1 and ground. Battery voltage should be present. If voltage reading is as specified, go to next step. If voltage reading is not as specified, check intermediate harness connectors B-124, C-210 and C-211 for damage. Repair or replace as necessary. If intermediate connectors are in good condition, repair open circuit or short circuit to ground in wiring harness between ignition switch harness connector terminal No. 2 and vehicle speed sensor harness connector terminal No. 1. After repairs, go to step 17.
10. Disconnect vehicle speed sensor harness connector. Check for continuity between vehicle speed sensor harness connector terminal No. 2 and ground. Resistance should be less than 2 ohms. If resistance is as specified, go to next step. If resistance is not as specified, repair wiring harness between vehicle speed sensor harness connector terminal No. 2 and ground. After repairs, go to step 17.
11. Disconnect vehicle speed sensor harness connector, combination meter harness connector, auto cruise control-ECU harness connector and A/C-ECU harness connector. Turn ignition on. Using DVOM, check voltage between vehicle speed sensor harness connector terminal No. 3 and ground. Voltage reading should be 4.8-5.2 volts. If voltage reading is as specified, go to next step. If voltage reading is not as specified, check intermediate connector for damage. Repair or replace as necessary. After repairs, go to step 17. If intermediate connector is in good condition, repair short circuit to ground or damage in wiring harness between vehicle speed sensor harness connector terminal No. 3 and ECM harness connector C-115 terminal No. 86. After repairs, go to step 17.
12. Check vehicle speed sensor. See VEHICLE SPEED SENSOR in SYSTEM & COMPONENT TESTING article. If vehicle speed sensor operates as specified, go to next step. If vehicle speed sensor does not operate as specified, replace vehicle speed sensor. After replacing sensor, go to step 17.
13. Check ECM harness connector C-115 for damage. Repair or replace as necessary. After repairs, go to step 17. If connector is in good condition, go to next step.
14. Check intermediate harness connectors B-124, C-210 and C-211. Repair or replace as necessary. After repairs, go to step 17. If intermediate connectors are okay, go to next step.
15. Check intermediate harness connector C-124. If intermediate connector is damaged, repair or replace as necessary. After repairs, go to step 17. If intermediate connector is okay, check for harness damage between vehicle speed sensor harness connector terminal No. 3 and ECM harness connector C-115 terminal No. 86. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 17.
16. Check for harness damage between vehicle speed sensor harness connector terminal No. 2 and ground. If wiring harness is in good condition, check for short to ground in wiring harness between vehicle speed sensor harness connector terminal No. 3 and other system. Repair as necessary. After repairs, go to next step. If circuit is okay, go to next step.
17. Using scan tool, check vehicle speed sensor. Connect scan tool to data link connector. Start the engine. Set scan tool to the data reading mode for data list item 24: VEHICLE SPEED SENSOR. Check that the speedometer and (MUT-II) display speed match when traveling at a vehicle speed of 25 MPH (40 KP/H). Turn ignition switch to LOCK position. If sensor is operating properly, inspection is complete. If sensor is not operating properly, repeat diagnosis.

Scheme 25

Check conditions are when vehicle is under closed loop idle speed control, engine coolant temperature is more than about 171°F (77°C), battery voltage is more than 10 volts, power steering pressure switch is off, volumetric efficiency is less than 40 percent, barometric pressure is more than 11 psi (76 kPa), intake air temperature is more than 14°F (-10°C), 60 seconds have elapsed from the start of the previous monitoring and target idle air control motor position is more than 100 steps.

Judgment criteria is when actual idle speed is more than 100 RPM less than the target idle speed for 12 seconds.

The most likely causes for this DTC to be set are

1. Idle air control motor failed.
2. Open or shorted idle air control motor circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

Scheme 26

1. Connect scan tool to data link connector. Turn ignition on. Set scan tool to read DTC. If a DTC other than P0506 is output, go to appropriate DTC test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-152075-S09950415582003011300000). If a DTC other than P0506 is not output, go to next step.
2. Check throttle body (throttle valve area). If throttle valve area is clean, go to next step. If throttle valve area is dirty, perform cleaning. After cleaning throttle valve, go to step 14.
3. Check idle air control motor harness connector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 14.
4. Disconnect idle air control motor harness connector. Using a DVOM, measure resistance between idle air control motor harness connector terminal No. 2 and either terminals No. 1 or No. 3. Standard value is 28-33 ohms at 68°F (20°C). Measure resistance between idle air control motor harness connector terminal No. 5 and either terminals No. 4 or No. 6. Standard value is 28-33 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace idle air control motor. After replacing idle air control motor, go to step 14.
5. Turn ignition off. Using DVOM, measure voltage between ground and idle air control motor harness connector terminals No. 2 and 5. Battery voltage should be present. If voltage reading is not as specified, go to next step. If voltage reading is as specified, go to step 7.
6. Check connector B-12X at MFI relay for damage. Relay is located in underhood fuse/relay block. Repair or replace as necessary. After repairs, go to step 14. If connector is in good condition, repair open circuit or short circuit to ground in circuit between MFI relay connector B-12X terminal No. 4 and idle air control motor harness connector terminals No. 2 and 5. After repairs, go to step 14.
7. Do not disconnect ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T). Using DVOM, measure voltage between ground ECM harness connector terminals No. 4, 5, 17 and 18 (M/T) or PCM harness connector terminals No. 14, 15, 28 and 29 - A/T) by backprobing. Voltage reading should be one volt or less for about 3 seconds, then change to battery voltage when ignition switch is turned from off to on position. If voltage reading is not as specified, go to next step. If voltage reading is as specified, go to step 10.
8. Check PCM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T) for damage. If connector in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 10.
9. Check for open circuit or short circuit to ground between idle air control motor harness connector and ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T). See «IDLE AIR CONTROL MOTOR CIRCUIT TERMINAL IDENTIFICATION»(ref-152075-S10715511892003011300000) table. Repair as necessary. After repairs, go to step 10. If wiring harness is in good condition, replace ECM (M/T) or PCM (A/T). After replacing ECM or PCM, go to step 10. IDLE AIR CONTROL MOTOR CIRCUIT TERMINAL IDENTIFICATION Idle Air Control Motor Connector B-104 Terminal No. ECM Connector C-121 Terminal No. (M/T) PCM Connector C-120 Terminal No. (A/T) 1 4 14 3 17 28 4 5 15 6 18 29
10. Check ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 10. If connector is in good condition, go to next step.
11. Remove idle air control motor. Connect Special Tool (MB991709) to idle air control motor. (Scheme 29) All terminals should be connected. Use the jumper wires to connect terminal No. 2 of the idle air control motor connector to battery voltage. Ensure that motor operates when terminals No. 1 and 3 of idle air control motor connector are respectively connected to the battery negative terminal using a jumper wire. Vibration should be present at each application of voltage to test clip combination. Use jumper wires to connect terminal No. 5 of the idle air control motor connector to battery voltage. Ensure that motor operates when terminals No. 4 and 6 of the idle air control motor connector are respectively connected to battery negative terminal using a jumper wire. Vibration should be present at each application of voltage to test clip combination. Install idle air control motor. If idle air control motor is operating properly, go to next step. If idle air control motor is not operating properly, replace idle air control motor. After replacing idle air control motor, go to step 14.
12. Check for harness damage between MFI relay connector B-12X terminal No. 4 and idle air control motor harness connector terminals No. 2 and 5. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 14.
13. Check for harness damage between idle air control motor harness connector B-104 and ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T). See «IDLE AIR CONTROL MOTOR CIRCUIT TERMINAL IDENTIFICATION»(ref-152075-S10715511892003011300000) table. If wiring harness is in good condition, replace ECM (M/T) or PCM (A/T). After replacing ECM or PCM, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to next step.
14. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0506 is output, repeat diagnosis. If DTC P0506 is not output, inspection is complete.

Check conditions are when vehicle speed has reached 0.93 MPH (1.5 KP/H) or more at least once, vehicle is under closed loop idle speed control, engine coolant temperature is more than 170°F (77°C), battery voltage is more than 10 volts, barometric pressure is more than 11 psi (76 kPa), intake air temperature is more than 14°F (-10°C), 60 seconds have elapsed from the start of the previous monitoring and target idle air control motor position is zero steps.

Judgment criteria is when actual idle speed has continued to be more than the target idle speed by 200 RPM or more for 12 seconds if the maximum air temperature during the previous operation was less than 113°F (45°C).

Judgment criteria is when actual idle speed has continued to be more than the target idle speed by 300 RPM or more for 12 seconds if the maximum air temperature during the previous operation was more than 113°F (45°C).

Troubleshooting Hunts

The most likely causes for this DTC to be set are

1. Idle air control motor failed.
2. Open or shorted idle air control motor circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

1. Connect scan tool to data link connector. Turn ignition on. Using scan tool, read DTC. If any DTC other than P0507 is output, perform appropriate DTC test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-152075-S09950415582003011300000). If any DTC other than P0507 is not output, go to next step.
2. Check intake system vacuum leaks. Repair as necessary. After repairs, go to step 14. If no vacuum leak is found, go to next step.
3. Check idle air control motor harness connector for damage. Repair or replace as necessary. After repairs, go to step 14. If connector is in good condition, go to next step.
4. Disconnect idle air control motor harness connector. Using a DVOM, measure resistance between idle air control motor harness connector terminal No. 2 and either terminals No. 1 or 3. Standard value is 28-33 ohms at 68°F (20°C). Measure resistance between idle air control motor harness connector terminal No. 5 and either terminals No. 4 or 6. Standard value is 28-33 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace idle air control motor. After replacing idle air control motor, go to step 14.
5. Turn ignition on. Using DVOM, measure voltage between ground and idle air control motor harness connector terminals No. 2 and 5. Battery voltage should be present. If battery voltage is not present, go to next step. If battery voltage is not present, go to step 7.
6. Check connector B-12X at MFI relay for damage. Repair or replace as necessary. After repairs, go to step 14. If connector is in good condition, repair open or short circuit to ground in wiring harness between MFI relay connector B-12X terminal No. 4 and idle air control motor harness connector terminals No. 2 and/or No. 5. After repairs, go to step 14.
7. Do not disconnect ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T). Measure voltage between ECM harness connector C-121 terminals No. 4, 5, 17 and 18 (M/T) or PCM harness connector C-120 terminals No. 14, 15, 28 and 29 (A/T) and ground by backprobing. Voltage reading should be one volt or less for about 3 seconds, then change to battery voltage when ignition switch is turned from off to on position. If voltage reading is not as specified, go to next step. If voltage reading is as specified, go to step 10.
8. Check ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 14. If connector is in good condition, go to next step.
9. Check for open or short circuit to ground between idle air control motor harness connector and ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T). See «IDLE AIR CONTROL MOTOR CIRCUIT TERMINAL IDENTIFICATION»(ref-152075-S10715511892003011300000) table. Repair circuit as necessary. After repairs, go to step 14. If wiring harness is in good condition, replace ECM (M/T) or PCM (A/T). After replacing ECM or PCM, go to step 14.
10. Check ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 14. If connector is in good condition, go to next step.
11. Check idle air control motor operation using Special Tool (MB991709). Remove idle air control motor. Connect special tool to idle air control motor. (Scheme 29) All terminals should be connected. Use jumper wires to connect terminal No. 2 of idle air control motor connector to battery (+) terminal. Check to ensure that motor operates when terminals No. 1 and 3 of the idle air control motor connector are respectively connected to the battery (-) terminal using a jumper wire. Vibration should be present at each application of voltage to test clip combination. Use jumper wires to connect the terminal No. 5 of the idle air control motor connector to the battery (+) terminal. Check to ensure that the motor operates when terminals No. 4 and 6 of the idle air control motor connector are respectively connected to the battery (-) terminal using a jumper wire. Vibration should be present at each application of voltage to test clip combination. If idle air control motor is operating properly, go to next step. If idle air control motor is not operating properly, replace idle air control motor. After replacing idle air control motor, go to step 14.
12. Check for harness damage between MFI relay connector A-18X terminal No. 4 and idle air control motor connector B-104 terminals No. 2 and 5. If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 14.
13. Check for harness damage between idle air control motor harness connector and ECM harness connector C-121 (M/T) or PCM harness connector C-120 (A/T). See «IDLE AIR CONTROL MOTOR CIRCUIT TERMINAL IDENTIFICATION»(ref-152075-S10715511892003011300000) table. If wiring harness is in good condition, replace ECM (M/T) or PCM (A/T). If wiring harness is not in good condition, repair as necessary. After repairs, go to next step.
14. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P0507 is output, repeat diagnosis. If DTC P0507 is not output, inspection is complete.

Scheme 27

Check conditions are when engine coolant temperature is more than 86°F (30°C), drive for 4 seconds or more with the vehicle speed at 31 MPH (50 KP/H) or more and stop vehicle, vehicle speed is 0.93 MPH (1.5 KP/H) or less. Repeat 10 times or more. Judgment criteria is when power steering pressure switch continues to be ON.

The most likely causes for this DTC to be set are

1. Power steering pressure switch failed.
2. Open or shorted power steering pressure switch circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

1. Connect scan tool to data link connector. Start and operate engine at idle. Set scan tool to the data reading mode for data list item 27: POWER STEERING PRESSURE SWITCH. If steering wheel is not turned while idling, OFF will be displayed. If steering wheel is turned while idling, ON will be displayed. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) . If sensor is not operating properly, go to next step.
2. Do not disconnect PSPS switch harness connector. Start and operate engine at idle. Using a DVOM, measure voltage between ground and PSPS sensor harness connector terminal No. 1 by backprobing. When steering wheel is not turned, battery voltage should be present. When steering wheel is turned, voltage reading should be one volt or less. If voltage reading is as specified, go to next step. If voltage reading is not as specified, go to step 5 .
3. Check PSPS switch harness connector for damage. Repair or replace as necessary. After repairs, go to step 14 . If connector is in good condition, go to next step.
4. Start and operate engine at idle. Set scan tool to the data reading mode for data list item 27: POWER STEERING PRESSURE SWITCH. If steering wheel is stopped while idling, OFF will be displayed on scan tool. If steering wheel is turned while idling, ON will be displayed on scan tool. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) . If sensor is not operating properly, replace ECM (M/T) or PCM (A/T). After replacing ECM or PCM, go to step 14 .
5. Check PSPS harness connector for damage. Repair or replace as necessary. After repairs, go to step 14 . If connector is in good condition, go to next step.
6. Disconnect PSPS harness connector. Turn ignition on. Measure voltage between terminal No. 1 and ground. Battery voltage should be present. If voltage is as specified, go to step 11 . If voltage is not as specified, go to next step.
7. Do not disconnect ECM harness connector C-119 (M/T) or PCM harness connector C-118 (A/T). Disconnect PSPS harness connector. Turn ignition on. Measure voltage between ground and ECM harness connector C-119 terminal No. 37 (M/T) or PCM harness connector C-118 terminal No. 52 (A/T) by backprobing. Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, go to step 9 .
8. Check ECM harness connector C-119 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is damaged, repair or replace as necessary. After repairs, go to step 14 . If connector is okay, repair open circuit in wiring harness between PSPS harness connector terminal No. 1 and ECM harness connector C-119 terminal No. 37 (M/T) or PCM harness connector C-118 terminal No. 52 (A/T). After repairs, go to step 14 .
9. Check ECM harness connector C-119 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 14 .
10. Check for short circuit to ground between PSPS harness connector terminal No. 1 and ECM harness connector C-119 terminal No. 37 (M/T) or PCM harness connector C-118 terminal No. 52 (A/T). If wiring harness is in good condition, replace ECM (M/T) or PCM (A/T). After replacing ECM or PCM, go to step 14 . If wiring harness is not in good condition, repair as necessary. After repairs, go to step 14 .
11. Replace PSPS. After replacing PSPS, check trouble symptoms and DTCs. If DTC P0551 is output, go to next step. If DTC P0551 is not output, go to step 14 .
12. Check ECM harness connector C-119 (M/T) or PCM harness connector C-118 (A/T) for damage. Repair or replace as necessary. After repairs, go to step 14 . If connector is in good condition, go to next step.
13. Check for harness damage between power steering pressure switch harness connector terminal No. 1 and ECM harness connector C-119 terminal No. 37 (M/T) or PCM harness connector C-118 terminal No. 52 (A/T). If wiring harness is in good condition, replace ECM (M/T) or PCM (A/T). After replacing ECM or PCM, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to next step.
14. Start and operate engine at idle. Set scan tool to the data reading mode for data list item 27: POWER STEERING PRESSURE SWITCH. If the steering wheel is not turned while idling, OFF will be displayed. If the steering wheel is turned while idling, ON will be displayed. Turn ignition switch to LOCK position. If switch is operating properly, inspection is complete. If switch is not operating properly, repeat diagnosis.

Check conditions are when engine coolant temperature is higher than 86°F (30°C) and vehicle speed is higher than 31 mph (50 KP/H). Judgement criteria is when the ON/OFF frequency of a power steering pressure switch is 10 Hz or more for 20 seconds.

The most likely causes for this DTC to be set are

1. Power steering pressure switch failed.
2. Air entered into power steering system.
3. Open or shorted power steering pressure switch circuit or loose connector.
4. ECM (M/T) or PCM (A/T) failed.

1. Connect scan tool (MB991502) to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 27, Power Steering Pressure Switch. If the steering wheel is stopped while idling, "OFF" will be displayed. If the steering wheel is steered while idling, "ON" will be displayed. Turn the ignition off. If the sensor is operating properly, it can be assumed that the malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) . If the sensor is malfunctioning, go to the next step.
2. Check the power steering fluid level. If the system is normal, go to the next step. If there are problems, correct them and proceed to step 7 .
3. Check the power steering pressure switch. If the system is normal, go to the next step. If the power steering pressure switch is not functioning normally, replace it and proceed to step 7 .
4. Check the oil pump pressure. If the system is normal, go to the next step. If the oil pump pressure is abnormal, make repairs and proceed to step 7 .
5. Check connector B-116 at the power steering pressure switch and connector C-119 at ECM (M/T) or connector C-113 at PCM (A/T) for damage. If the connector is in good condition, go to the next step. If the connector is damaged, repair or replace it and proceed to step 7 .
6. Check for harness damage between power steering pressure switch connector B-116 (terminal No. 1) and ECM connector C-119 (terminal No. 37 - M/T) or PCM connector C-118 (terminal No. 52 - A/T). If the harness wire is in good condition, replace the ECM (M/T) or PCM (A/T), otherwise, repair the damaged harness wire. Go to the next step.
7. Connect scan tool (MB991502) to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 27, Power Steering Pressure Switch. If the steering wheel is stopped while idling, "OFF" will be displayed. If the steering wheel is steered while idling, "ON" will be displayed. Turn the ignition off. If the switch is operating properly, the procedure is complete. If the switch is malfunctioning, repeat the troubleshooting.

Check conditions are that engine speed be higher than 50 RPM. Judgement criteria is input voltage from the generator FR terminal has continued to be approximately battery positive voltage for 20 seconds.

The most likely causes for this DTC to be set are

1. Open circuit in generator FR terminal circuit.
2. ECM (M/T) or PCM (A/T) failed.

1. Measure the voltage at generator intermediate connector B-14 by backprobing. Do not disconnect connector B-14. Start the engine and run at idle. Measure the voltage between terminal No. 1 and ground by backprobing. Engine: warming up Radiator fan: stopped Headlight switch: OFF to ON Rear defogger switch: OFF to ON Stoplight switch: OFF to ON Voltage should measure a drop. Turn the ignition off. If the measured voltage is within the specified range, go to the next step, otherwise, proceed to step 4 .
2. Check connector B-14 at generator intermediate connector for damage. If the connector is in good condition, go to the next step. If the connector is damaged, repair or replace it and proceed to step 11 .
3. Carry out a test drive with the drive cycle pattern (Other Monitor), see «OTHER MONITOR»(ref-152075-S37595059962003011300000) . Check the diagnostic trouble code. If DTC P1500 is set, replace the ECM or PCM and proceed to step 11 . If the DTC is absent, it can be assumed that this malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
4. Check connector B-14 at generator intermediate connector for damage. If the connector is in good condition, go to the next step, otherwise, repair or replace it and proceed to step 11 .
5. Check connector B-25 at generator connector for damage. If the connector is in good condition, go to the next step. If the connector is damaged, repair or replace it and proceed to step 11 .
6. Measure the voltage at generator harness side connector B-25. Disconnect connector B-25 and measure at the harness side. Turn the ignition on. Measure the voltage between terminal No. 4 and ground. Voltage should be battery positive voltage. Turn the ignition off. If battery positive voltage (approximately 12 volts are present, proceed to step 9 , otherwise, go to the next step.
7. Check connector C-119 at ECM (M/T) or connector C-118 at PCM (A/T) for damage. If the connector is in good condition, go to the next step, otherwise, repair or replace it and proceed to step 11 .
8. Check for open circuit and short circuit to ground between generator connector B-25 (terminal No. 4) and ECM connector C-119 (terminal No. 41 - M/T) or PCM connector C-118 (terminal No. 54 - A/T). If the harness wire is in good condition, replace the ECM or PCM, otherwise, repair the harness wire. Proceed to step 11 .
9. Check connector C-119 at ECM (M/T) or connector C-118 at PCM (A/T) for damage. If the connector is in good condition, go to the next step. If the connector is damaged, repair or replace it and proceed to step 11 .
10. Check for harness damage between generator connector B-25 (terminal No. 4) and ECM connector C-119 (terminal No. 41 - M/T) or PCM connector C-118 (terminal No. 54 - A/T). If the harness wire is in good condition, replace the generator, otherwise, repair the damaged harness wire. Go to the next step.
11. Connect scan tool (MB991502) to the data link connector. Turn the ignition on. Read the DTC. Turn the ignition off. If DTC P0622 is set, repeat the troubleshooting. If the DTC is absent, the inspection is complete.

Scheme 28

Note. This is only if engine coolant temperature is less than 32°F (0°C) when starting.

Check conditions are when 8 minutes or more have passed after starting the engine, engine coolant temperature is more than 113°F (45°C), intake air temperature is more than 32°F (0°C) and volumetric efficiency is 30-45 percent. Judgment criteria is when manifold differential pressure sensor output voltage has continued to be more than 4.6 volts, corresponding to an absolute pressure of 17 psi (118 kPa) or more for 2 seconds or manifold differential pressure sensor output voltage has continued to be less than 0.1 volt, corresponding to an absolute pressure of 0.3 psi (2.4 kPa) or less, for 2 seconds.

Note. This is only if engine coolant temperature is 32°F (0°C) or more when starting.

Check conditions are when 8 minutes or more have passed after starting the engine, engine coolant temperature is more than 113°F (45°C), intake air temperature is more than 32°F (0°C) and volumetric efficiency is less than 30 percent. Judgment criteria is when manifold differential pressure sensor output voltage has continued to be more than 4.2 volts, corresponding to an absolute pressure of 16 psi (108 kPa) or more, for 2 seconds.

Note. This is only if engine coolant temperature is 32°F (0°C) or more when starting.

Check conditions are when 8 minutes or more have passed after starting the engine, engine coolant temperature is more than 113°F (45°C), intake air temperature is more than 41°F (5°C) and volumetric efficiency is more than 70 percent. Judgment criteria is when manifold differential pressure sensor output voltage has continued to be less than 1.8 volts, corresponding to an absolute pressure of 4.6 psi (46 kPa) or less, for 2 seconds.

The most likely causes for this DTC to be set are

1. Manifold differential pressure sensor failed.
2. Open or shorted manifold differential pressure sensor circuit or loose connector.
3. ECM (M/T) or PCM (A/T) failed.

1. Using scan tool, check manifold differential pressure sensor. Connect scan tool to data link connector. Start the engine and run at idle. Set scan tool to the data reading mode for data list item 95: MANIFOLD DIFFERENTIAL PRESSURE SENSOR. While engine is idling, pressure should be 18-22 psi (62-76 kPa). Turn ignition switch to LOCK position. If sensor is operating properly, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) . If sensor is not operating properly, go to next step.
2. Check manifold differential pressure sensor harness connector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
3. Disconnect manifold differential pressure sensor harness connector. Turn ignition on. Using a DVOM, measure voltage between sensor harness connector terminal No. 3 and ground. Voltage reading should be 4.8-5.2 volts. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 6 .
4. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
5. Check for open or short circuit to ground between manifold differential pressure sensor harness connector terminal No. 3 and ECM harness connector C-115 terminal No. 81 (M/T) or PCM harness connector C-118 terminal No. 46 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 12 . If wiring harness is not in good condition, repair as necessary. After repairs, go to step 12 .
6. Check continuity at manifold differential pressure sensor harness connector terminal No. 2 and ground. Resistance should be less than 2 ohms. If resistance is as specified, go to step 9 . If resistance is not as specified, go to next step.
7. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
8. Check for open circuit and harness damage between manifold differential pressure sensor harness connector terminal No. 2 and ECM harness connector C-115 terminal No. 92 (M/T) or PCM harness connector C-118 terminal No. 57 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 12 . If wiring harness is not in good condition, repair as necessary. After repairs, go to step 12 .
9. Check ECM harness connector C-115 (M/T) or PCM harness connectors C-116 and C-118 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 12 .
10. Check for harness damage between manifold differential pressure sensor harness connector terminal No. 3 and ECM harness connector C-115 terminal No. 81 (M/T) or PCM harness connector C-118 terminal No. 46 (A/T). If wiring harness is in good condition, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to step 12 .
11. Check for open or short circuit to ground and harness damage between manifold differential pressure sensor harness connector terminal No. 1 and ECM harness connector C-115 terminal No. 73 (M/T) or PCM harness connector C-116 terminal No. 91 (A/T). If wiring harness is in good condition, replace manifold differential pressure sensor. After replacing sensor, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to next step.
12. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P1400 is output, repeat diagnosis. If DTC P1400 is not output, inspection is complete.

Scheme 29

Check conditions are when engine speed is greater than 50 RPM. Judgement criteria is when input voltage from the generator FR terminal has continued to be about battery voltage for 20 seconds.

The most likely causes for this DTC to be set are

1. Open circuit in generator FR terminal circuit.
2. ECM (M/T) or PCM (A/T) failed.

1. Do not disconnect generator harness connector. Start and operate engine at idle. Ensure engine is warmed up and radiator fan is stopped. Using a DVOM, measure voltage between generator harness connector terminal No. 3 and ground by backprobing. Check during the following conditions: Headlight switch turned from OFF to ON. Rear defogger switch turned from OFF to ON. Stoplight switch turned from OFF to ON. Voltage should drop when each switch is actuated. Turn ignition switch to LOCK position. If voltage is as specified, go to next step. If voltage is not as specified, go to step 4 .
2. Check generator harness connector for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 11 .
3. Check the trouble symptoms. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P1500 is output, replace ECM or PCM. After replacing ECM or PCM, go to step 11 . If DTC P1500 is not output, malfunction is intermittent. See «INTERMITTENT DIAGNOSTIC TROUBLE CODES»(ref-152075-S03521432692003011300000) .
4. Check generator harness connector for damage. Repair or replace as necessary. After repairs, go to step 11 . If connector is in good condition, go to next step.
5. Check generator harness connector for damage. Repair or replace as necessary. After repairs, go to step 11 . If connector is in good condition, go to next step.
6. Disconnect generator harness connector. Turn ignition on. Using DVOM, measure voltage between generator harness connector terminal No. 4 and ground. Battery voltage should present. Turn ignition switch to LOCK position. If voltage is not as specified, go to next step. If voltage is as specified, go to step 9 .
7. Check ECM harness connector C-119 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 11 .
8. Check for open or short circuit to ground between generator harness connector terminal No. 4 and ECM harness connector C-119 terminal No. 41 (M/T) or PCM harness connector C-118 terminal No. 54 (A/T). If wiring harness is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to step 11 . If wiring harness is not in good condition, repair as necessary. After repairs, go to step 11 .
9. Check ECM harness connector C-119 (M/T) or PCM harness connector C-118 (A/T) for damage. If connector is in good condition, go to next step. If connector is not in good condition, repair or replace as necessary. After repairs, go to step 11 .
10. Check for harness damage between generator harness connector terminal No. 4 and ECM harness connector C-119 terminal No. 41 (M/T) or PCM harness connector C-118 terminal No. 54 (A/T). If wiring harness is in good condition, replace generator. After replacing generator, go to next step. If wiring harness is not in good condition, repair as necessary. After repairs, go to next step.
11. Test the OBD-II drive cycle. Carry out a test drive with the drive cycle pattern. See «OTHER MONITOR»(ref-152075-S37595059962003011300000) under VERIFYING REPAIRS. Check for DTCs. If DTC P1500 is output, repeat diagnosis. If DTC P1500 is not output, inspection is complete.

Scheme 30

Note. When engine is started with the IOD or storage connector disconnected, the ECM (M/T) or PCM (A/T) judges that an open circuit has occurred in the battery backup line. Consequently, the SERVICE ENGINE SOON/MALFUNCTION INDICATOR LIGHT illuminates and DTC is stored in memory.

Check conditions are when starting sequence was completed and battery voltage is more than 10 volts. Judgement criteria is when battery backup line voltage has continued to be 6 volts or less for 2 seconds.

The most likely causes for this DTC to be set are

1. Open or shorted battery backup line or loose connector.
2. ECM failed (M/T) or PCM failed (A/T).

1. Turn ignition on. Using scan tool, erase/clear DTC. Start and operate engine at idle. Read DTC. Turn ignition switch to LOCK position. If DTC P1603 is output, go to next step. If DTC P1603 is not output, inspection is complete.
2. Check the backup power supply voltage at ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) by backprobing. Do not disconnect the ECM or PCM harness connector. Using a DVOM, measure voltage between ground and ECM harness connector C-115 terminal No. 80 (M/T) or PCM harness connector C-118 terminal No. 66 (A/T) by backprobing. Battery voltage should be present. If voltage is not as specified, go to next step. If voltage is as specified, go to step 5 .
3. Disconnect ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T). Measure voltage between terminal No. 80 (M/T) or 66 (A/T) and ground. Battery voltage should be present. If voltage is as specified, go to next step. If voltage is not as specified, check intermediate connectors C-05, C-123 and C-129 for damage. Repair or replace as necessary. After repairs, go to step 6 . If intermediate connectors are in good condition, repair open or short circuit to ground in wiring harness between battery and ECM harness connector C-115(M/T) terminal No. 80 or PCM harness connector C-118 (A/T) terminal No. 66. After repairs, go to step 6 .
4. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If harness connector in good condition, check intermediate connectors C-05, C-123 and C-129 for damage. Repair or replace as necessary. After repairs, go to step 6 . If intermediate connector are in good condition, repair damage to wiring harness between battery and ECM harness connector C-115 (M/T) terminal No. 80 or PCM harness connector C-118 (A/T) terminal No. 66. After repairs, go to step 6 .
5. Check ECM harness connector C-115 (M/T) or PCM harness connector C-118 (A/T) for damage. If harness connector is in good condition, replace ECM or PCM. After replacing ECM or PCM, go to next step. If harness connector is not in good condition, repair or replace as necessary. After repairs, go to next step.
6. Turn ignition on. Using scan tool, read DTC. Turn ignition off. If DTC P1603 is output, repeat diagnosis. If DTC P1603 is not output, inspection is complete.